July 12, 2021 • 55 mins
A listener asked to learn more about fast recharging technologies, so we take a look at the history and evolution of batteries, what happens with rechargeable batteries and the complicated mess of fast recharging solutions.
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Episode Transcript
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Speaker 1 (00:04):
Welcome to tech Stuff, a production from I Heart Radio.
Hey there, and welcome to tech Stuff. I'm your host,
Jonathan Strickland. I'm an executive producer with I Heart Radio
and I love all things tech and I end nearly
every episode of tech Stuff asking y'all if there are
(00:26):
any topics you'd like to hear me explain on the show.
And recently a lot of you have been sending in requests,
which is awesome, and I'm getting to those now that
those tech glossary episodes are all done. And first up
is a message from Brian Perez, who wants to know
about fast charging technology, which is a great and legitimately
(00:47):
confusing suggestion because there are a lot of different technologies
out there. So today we're gonna talk about how batteries work,
because that's important for us to understand this technology. Then
we're gonna talk more about how rechargeable batteries work, because
clearly that's going to be important. And then we'll talk
(01:08):
about what makes fast charging possible and some of the
different technologies that are out on the market and why
it's such a mess. Uh So let's do that, and
we'll start with the basics of electricity and that lovely
equation that tells us that wattage that that's a measurement
of power, is equal to current in ampiers times voltage
(01:33):
or volts, And it's good to remember the difference between
current and volts. Current refers to the amount of electric
current moving across a circuit, and voltage is the force
that drives that current. So frequently folks like me use
the analogy of water pressure to describe voltage and the
amount of water actually flowing through a system to describe current.
(01:57):
Uh So, voltage is sort of the umph at which
current gets pushed. We'll come back to the watch discussion
towards the end of this episode, because that's really at
the heart of fast charging technology. So let's talk about
how batteries work in general and the evolution of the battery. Now,
(02:17):
one thing we have to keep in mind is that
batteries don't create energy. Energy can be neither created nor destroyed.
Batteries store energy in the form of chemical energy. They
release energy in the form of electricity. So we're really
talking about converting one type of energy into another. That
(02:39):
is possible, right. We can't create or destroy energy, but
we can change it from one form to another. So
that's the heart of what batteries do. Batteries go through
an electro chemical reaction and through that process they release
electrons i eat. Electricity. The reaction takes play, and electrons
(03:01):
are a byproduct. They are released as part of this
chemical reaction. Even when a battery isn't being used, this
reaction can still occur, though typically at a very much
slower rate. Right otherwise, batteries would be dead before you
ever got a chance to use them, but it does happen.
This is called self discharge. This is one of the
(03:23):
factors that determines the shelf life of a battery. So
if you ever look at just a long list of
all the different types of batteries, you'll typically see the
listed you know, average shelf life of them, and if
it's a shorter shelf life, that tells you that there's
a higher rate of of self discharge. Generally speaking, that's
(03:44):
actually being a little too reductive because it also depends
on the capacity of the battery, like how how much
volume does the battery have, But we're not going to
dive too deep into all of that. So batteries that
are in hot environ ments also tend to self discharge
at a faster rate than batteries that are in a
colder environment, So you don't want your batteries to be
(04:07):
in someplace that's going to be really hot. However, this
also leads some people to make a decision that is
not very wise. It is not a good idea to shove,
you know, unused batteries in the freezer so that you
can make them last longer. The lower temperatures that the
batteries experience. That means that it will impede the chemical
(04:30):
reaction when you plug it into something. So this means
that a cold battery will not perform as well as
a normal battery until it gets up to temperature. And
when I say that the battery will eventually go dead
through self discharge, often we are talking about a factor
about years, right, So self discharge doesn't happen overnight. There's
(04:51):
no reason to put batteries into the fridge or the
freezer or anything like that, because you're likely going to
use them before they would have self discharged anyway. Setting
aside stories about you know, ancient Babylonian containers that might
have been used as some sort of proto battery, possibly
for the purposes of electro plating materials. The ancestor of
(05:15):
the modern battery really took shape in sevent with Alessandro Volta,
and his name gives us the word volt. More importantly,
our history starts with a disagreement between two scientific thinkers,
and those thinkers were Volta and Luigi Galvani. Now, Galvani
(05:36):
had observed in the seventeen eighties that if he were
to take a frog that was really most sincerely dead
and expose said dead froggy's leg muscles by you know,
cutting away the skin and then touching that muscle with
an arc made from iron and brass, it would cause
the muscle to twitch. Now, Galvani had already run experiments
(06:00):
using things like an electrostatic generator, so a device that
generates an electrostatic charge, and he knew that there was
some connection between muscular movement and electricity because of this.
But this was different, right because he was using what
appeared to be an inert pair of metals. It was
an iron embrass, and there was no electro static machine
(06:21):
generating a charge. He wasn't even doing this during a thunderstorm.
He had observed that thunderstorms could also produce electrostatic charges
that could then influence experiments like these, But this was
a case where neither of those things were components. So
he said, the electricity must reside within the muscle itself.
(06:41):
If it's not in the iron embrass, it's gotta be
in the muscle, and Volta thought that his buddy Galvani
was totally on the wrong track. Volta's assertion was that
the cause of the twitching was due to the use
of two different metals that were connecting to one another
through the medium of a moist conductive UH substance, that
(07:04):
being the froggy's leg muscle. So Volta decided to experiment
in the field of electrochemical reactions to see if perhaps
he was right and if Galvanni was wrong. So Galvanni,
by the way, was totally right in that muscle movements
are the result of electrochemical processes, but in this case
Volta was saying, yeah, but that's not what's happening here.
(07:26):
I don't think you're you're making the right hypothesis. So
Volta created a stack of material He alternated layers of
zinc UH. He then put in some cardboard that had
been soaked in brine, and then he would put on
layers of silver. So he kind of alternated with these,
and he was able to create a kind of proto
(07:46):
battery that we refer to with the charming name of
voltaic pile. There were some pretty big limitations to this, however.
The strength of this battery depended in part on the
number of layers that he could build up. However, he
couldn't make it too tall, because the layers on top
would start to press down so hard on the layers
(08:09):
below that the brine in that cardboard would get squeezed out,
and then it would suddenly be less effective. Also, the
metal would corrode fairly quickly due to the electrochemical reactions,
and uh, the the byproduct would build up on those plates,
and eventually they would impede the reaction from continuing, and
(08:32):
you'd see a decrease in electrical output because of it. Now,
just a few decades after Volta's work, there was an
English chemist named John Frederick Danielle who made an or Daniel.
I suppose it doesn't have an E at the end,
so I'll say daniel it's d A N I E
L l uh. He made an early battery using a
(08:54):
plate of copper, a plate of zinc, and some gnarly chemicals.
Let's see if I can paint a mental picture. So
he took a big glass jar and at the bottom
of the inside of this jar he put the copper plate,
so the copper plates at the bottom. On top of
the copper plate, he poured in a solution of copper sulfate.
(09:14):
By the way, these days, copper sulfate is used in
stuff like herbicides because it kills plants pretty darn effectively. Also,
when we're talking about batteries, were often talking about chemicals
that are acidic. That is pretty common. You've probably heard
about battery acid and it's one of the many reasons
why you don't want to mess around, you know, cutting
(09:36):
open batteries and stuff. There are a lot of reasons
for that, specifically when you get the things like lithium
ion batteries and um that's one of the many ones.
So then he then on top of this copper sulfate solution,
he poured in a zinc sulfate solution. Now, copper sulfate
has a greater density than zinc sulfate, so the copper
(09:57):
sulfate settled down at the bottom of the jar, and
the zinc sulfate floated to the top. You've probably seen
like mixtures of oil and water that do this kind
of thing. Daniel then suspended a zinc plate within these
zinc sulfate half of the jar. So imagine like a
hook that hooks over the side of the jar, and
hanging from that hook is a plate of zinc held
(10:20):
horizontal above the copper sulfate level. Right, So you've got
two separate levels here, and two separate sulfates uh to
each plate. He attached a conductive wire. And now we
need a bit of an anatomy lesson for batteries. So
let's consider your typical battery. Let's say that you just
(10:42):
if you happen to have a battery nearby, you can
even look at one and and kind of get the
lay of the land. So you've got two terminals with
your battery, Like if it's a double a battery, it's
on either end of the battery. Right. These are the
points of the batteries that connect to a circuit or
or a load. This is the pathway that electrons will
take where at some point along the way they will
(11:04):
presumably do some sort of work. So you've got a
positive terminal and you've got a negative terminal. You could
connect these two terminals directly to each other with conductive wire,
but that's not a great idea. That would lead to
the battery discharging very rapidly, and for some tymes of batteries,
that could be dangerous as the battery will heat up
(11:24):
from the rapid electrochemical reaction, potentially leading to combustion or explosion.
So not a good idea to do this. Attached to
the positive terminal inside the battery is the cathode. Connected
to the negative terminal inside the battery is the annode. Together,
these are the electrodes of the battery. There's a separator
(11:46):
that keeps those two electrodes from touching. Otherwise we would
have a very similar situation to what I was talking
about before, where you connect the two terminals with a
conductive wire, only in this case it would be internal
inside the battery as opposed to connect did through an
external wire. The separator does allow an electric charge to
flow between the two electrodes. Uh. There's also a medium
(12:08):
called the electrolyte that facilitates the flow of electric charge.
So during discharge, The anode reacts with the electrolyte and
experiences and oxidation reaction. Ions that is, atoms or molecules
that carry an electric charge from the electrolyte will react
with the anode and that produces a new compound between
(12:31):
the two and in this process also releases electrons. So
now we've got our supply of electrons popping over onto
the cathode side. The cathode goes through a reduction reaction
in which ions, electrons, and the cathode begin to form compounds.
This process takes in electrons while the process that the
anode generates electrons, but the separator keeps the electrons from
(12:54):
just rushing over from one side to the other. Right,
you would think, all right, if we've gotten excess of
electrons and like charge repels like, then the electrons don't
want to be next to each other, right, they'd rather
get to the other side, especially as that side grows
more positive because the electrons are negative and opposite charges attract.
But the separator prevents the electrons from doing this. They
(13:17):
can't get to that side unless you open a pathway
for them. That pathway is the circuit. So when you
open up a circuit. You create a circuit that goes
connects between these two electrodes. Now the electrons have a
way to get away from the negatively charged side of
the battery and head to the positive charged side of
the battery, and they will do that even if it
(13:39):
means they have to do some work along the way.
Thus we have batteries. So with Daniels battery, which we
call the Daniel cell, the wire connected to the zinc
plate served as the negative terminal. The wire attached to
the copper plate at the bottom of the jar was
the positive terminal. And the cell worked really well. But
because we're talking about liquid components here, it couldn't really
(14:01):
be used in any sort of application that the thing
would be moved around because it would just be slashing everywhere, right,
So it had to be stationary, and that really limited
what you could do with this kind of battery. A
few decades later brings us up to the eighteen sixties.
That's when George Leshan switched things up by making a
(14:22):
battery out of a porous pot. He took some crushed
manganese dioxide with a little bit of carbon in it,
and he used that as the cathode. He packed that
onto the inside of the porous pot. The annode was
a zinc rod that was actually kept separate from the pot.
So you had a pot on the inside of which
(14:43):
was this mixture of manganese dioxide and carbon, and then
you have this zinc rod. Then he leant put both
the pot and the zinc rod into another container filled
with ammonium chloride that acted as the electrolyte. Now, this
solution of amonium chloride seeped through the porous pot to
(15:03):
make contact with the cathode and that allowed the electrochemical
process to begin and the carbon rod that would also
be inserted into this Uh, this pot acted as a
collector for the electrons. So that's what you would use
to you know, direct the electrons outward to whatever circuit.
This type of battery saw widespread use in telegraph stations,
(15:26):
but still relied on a liquid electrolyte, and UH that
really made it unsuitable for stuff what moved around a lot,
so still not ideal. We would see all that change
thanks to the work of inventor Carl Gossner from Germany.
I originally put in my notes that he was a
German inventor, But now that I read that, it sounds
(15:49):
like he invented Germans, and I'm pretty sure they were
around before him. Anyway, Gassner made several improvements to batteries,
and that meant that they would be practical in many
of our applications. For one thing, Gastner had the bright
idea to use zinc as the container material for the
battery itself. So the body of the battery was made
out of zinc and it also served as the negative electrode,
(16:12):
so it was doing double duty. It was the container
and the negative electrode, so the actual body of the
battery served as one of the two electrodes the anode.
In case you're trying to keep these things straight. Inside
the battery, he put in a folded paper sack which
served as the separator, which kept the interior of the
zinc case separate from the electrolyte. For the cathode, he
(16:34):
used a mixture of manganese ox side and in the
middle of this he suspended a carbon rod, which again
acted as the electron collector. And later he would add
zinc chloride to the electrolyte because it reduced the rate
at which the electro light would corrode the zinc uh
of the case. It would It would then extend the
batteries useful life by slowing down that that process. But
(16:59):
the most important part of this invention was that Gasner's
battery is what we call a dry cell battery. It
was not full of sloshy liquid. Even though the electrolyte
was sort of a jelly liquid e kind of thing,
the rest of it was all dry. I meant that
you didn't have to worry about the battery components slash
galt all over the place, admit that you could invert
it and it would still work. It opened up a
(17:20):
lot of applications for batteries. In the eighteen nineties, the
National Carbon Company, a US based organization, developed the Columbia
dry cell battery, which was another improvement. They first started
making La Sanche batteries in the eighteen nineties, but again
those were wet cell batteries. An engineer at the company
(17:40):
named E. M. Jewitt created a one point five volt
dry cell battery and got the blessing from the company
to make a commercial version that they could actually sell.
So in eighteen nine six NCC began selling a one
and a half volt six inch long dry cell battery. Interestingly,
the National Car been Company would buy a fifty steak
(18:02):
in another company called the American Electrical Novelty and Manufacturing Company.
The battery making part of that company joined in CC
and together they became known as ever Ready, and much
later that company would change its name to Energizer, So
that one dates all the way back to the early
nineteen hundreds. All the batteries I mentioned so far are
(18:23):
what we call primary batteries. So a primary battery is
a one use battery. That means once the battery goes dead,
it's really most sincerely dead. It's not coming back because
we're talking about a different chemical component reacting with another
chemical component to produce electricity, and then you get by
(18:46):
products as well, and you eventually run low enough on
those initial chemical components that you're not getting enough juice
and there's no way to reverse that process. Right once
it turns into the byproducts, the battery has become a nert.
Now a few things that can that can happen to
make a battery less effective. One is that, as I mentioned,
(19:09):
you could have your chemical agents depleted in the battery,
So what you've got now is essentially a container just
filled with useless goop as a result of all these
electrochemical reactions taking place. Another is that whatever you're using
as an electron collector might get covered in deposits, and
that blocks the collector's ability to collect electrons. And so
(19:31):
you might still have some viable juice in the battery,
but because of this corrosion coding elements inside the battery,
it's not able to have that that process go effectively.
Corrosion is also an issue as well for the electrodes.
If you've ever had an old battery and something and
you've just seen this gross kind of build up on it,
(19:53):
that's often the corrosion I'm talking about. And all of
these things lead to a batteries and ability to produce current.
With primary batteries, there's really no way to reverse this process.
The electrochemical reactions will stop, and then you've got to
toss the battery. Primary batteries tend to be relatively inexpensive.
They also tend to have a fairly long shelf life,
(20:15):
but they're also wasteful. When we come back, we'll talk
about secondary batteries, also known as rechargeable batteries. But first,
let's take a quick break. When I was talking earlier
about the development of the battery, the last inventor I
(20:37):
mentioned was Carl Gassner, who invented the dry cell battery,
which was in but the rechargeable battery actually predates the
dry cell battery, and the person who generally gets the
credit for inventing them is Gaston Plante. No one invents
like Gaston or imprints like guests. Okay, I'll never mind.
(21:00):
In eighteen fifty nine, he created a lead acid battery
that you could actually recharge his batteries and ode was
made of a sheet of lead, and he used a
sheet of lead dioxide for the cathode, and he placed
a linen cloth between those two sheets. Then he rolled
this into a cone shaped spiral. He immersed this cone
(21:21):
in a solution of sulfuric acid, which is pretty dangerous stuff,
and the chemical reaction that resulted released electrons and boom,
you get yourself a battery. Gaston discovered that if he
applied a charge to this battery so that current flowed
into the battery, it would actually reverse the electrochemical reaction
that produced the electrons. This battery then had a way
(21:44):
to discharge and then recharge. In eighteen sixty he presented
a nine cell battery to the French Academy of Sciences,
and his peer Camille Alphonse for continued to work on
the invention and saw it actually become a commercial product.
Camille would later make improvements to this battery, including a
process that would increase the battery's capacity for storing electricity.
(22:07):
And we still use lead acid batteries today. It's the
type of battery you find in your typical internal combustion
engine vehicle. So your typical car that has an internal
combustion engine also has a lead acid battery. Now, I
mentioned that Gaston created a nine cell battery, and that
is something that we should chat about for just a moment.
Some batteries, like car batteries, consist of multiple cells that
(22:32):
connect to one another within the battery itself. So a
typical car battery would have six cells connected in series.
If you connect batteries in series, you increase the voltage
that those batteries produce. Now, remember, voltage is kind of
like pressure. That's how much umph is behind an electrical current,
(22:53):
but it's not a measure of the amount of current itself.
So you're not increasing the current by adding batteries or
mattery cells in series. You're increasing the voltage. If you
add them in parallel, it's different. But we're talking about
in series one after the other. So your typical lead
acid battery has cells that individually have a voltage of
(23:15):
two volts, but because they are connected in series, the
battery overall has a voltage of twelve volts. Right, you've
got six cells each two volts. You've got them in series,
so it multiplies the voltage to twelve. Most of your
typical household batteries, like double as, triple AS, C and
D batteries, those typically come in at one and a
(23:35):
half volts. But again, if you connect them in series,
you get more voltage. So a flashlight that has two
batteries connected in series is actually relying on three volts
for the voltage. Another thing we should touch on is
that because batteries convert chemical energy into electrical energy, there's
a fundamental limit as to how much juice a battery
(23:58):
can hold. That doesn't mean all batteries are equal. Depending
on the materials used to create that electrochemical reaction, you
can get more efficient and energy dense batteries. For example,
lead acid batteries don't really have great energy density, which
you typically measure either by comparing how much energy the
battery can store compared to that batteries mass, or how
(24:22):
much energy it can store compared to that batteries volume.
There are two different ways of looking at it. Alkaline batteries,
which make up a lot of the typical batteries we
use today, the non rechargeable primary batteries that we use today,
those are better from an energy density metric, meaning, based
on that batteries mass or volume, it can hold more
(24:45):
energy than a lead acid battery. But we also have
to keep in mind that these are much smaller than
lead acid batteries. The batteries power density and energy density
depend on the mass and volume of the battery and
the type of chemical components that make up the anode,
the cathode, and the electrolyte. So we're ultimately talking about
a chemical physical process that relies on a limited amount
(25:08):
of source material, like a limited amount of fuel, if
you will. So this means that it's very hard to
make longer lasting batteries based on what we have today,
unless you're making literally just larger batteries. You can't really
squeeze more out of physics. It's just you're you're hitting
the fundamental limits of what is possible in a chemical reaction. Now,
(25:33):
in tech, we've got Moore's law, which we generally interpret
as meaning that every two years or so, the processing
power or processing speed of computers tends to double. That's
the very you know, dumbed down version of Moore's law,
but that's kind of how we interpret it today. But
we do not see batteries on a similar trajectory, right.
(25:55):
We don't see batteries increase in capacity at the same
rate as we're seeing processing speed or processing power. This
is because the laws of physics don't really care if
we need better batteries, which puts pressure on electronics manufacturers
too really create ways to limit how much electricity gadgets
actually require as they operate. Not just electronics manufacturers, but
(26:19):
also you know, the companies that design things like operating systems.
In order to make batteries last longer. You can't just
build better batteries. That's that's that's a much slower process.
It means that you have to be smarter with how
much energy you try to access so barring some miraculous
(26:39):
alien technology, we're not likely to see astronomical improvements to
battery life, though there are people who are working on it.
It's just we're not likely to see giant leaps there.
So that means we just have to be smarter about
how our gadgets access power. Often when we're talking about
rechargeable batteries, we are thinking about bowl devices like smartphones, tablets,
(27:02):
laptops and handheld gaming systems and that kind of thing.
These devices almost exclusively today rely on lithium ion batteries. Now,
if you were able to look inside a battery, and
I urge you to never ever ever do this because
there is dangerous stuff in those batteries, but you would
see that the battery consists of layers of carbon graphite
(27:25):
and lithium on the anode side. This is on the
negative terminal side of the battery, and we refer to
the arrangement of lithium that's kind of nestled between lattices
of carbon graphite as intercalation. So they're intercalated between these layers.
You can think of like the carbon graphite as being
almost like a net and the little lithium atoms are
(27:47):
nestled inside between layers of this net. Lithium has three electrons,
and you might remember from basic science class that electrons
orbit the nucleus of an atom within certain energy shells,
and that only a specific number of electrons can inhabit
each shell. For for the shell that's closest to the nucleus,
you can only have two electrons. So that means that
(28:10):
each lithium atom has two electrons in that first energy shell,
and there's a single lonely electron that's orbiting the nucleus
in the next energy shell out from the nucleus. That
also means it's pretty easy for lithium to give up
that electron. It's not holding onto its super hard. That
means the lithium atom, when it lets go of this electron,
(28:32):
becomes an ion. It's a charged atom of lithium, a
positively charged one in this case, because it's given up
an electron which carries a negative charge, but it's held
onto all of its protons, which have positive charges. So
when a lithium ion battery connects to a circuit and
that circuit becomes complete, the outermost electrons in the lithium
(28:53):
atoms go through the pathway of the circuit and leave
the lithium atoms now ions behind and head towards the
positively charged cathode side of the battery. That's because the
electrons carry that negative charge and negative is attracted to positive,
and the lithium ions left behind they do have that
positive charge to them. That will become important in a second. Now,
(29:15):
the cathode is positively charged because there is cobalt there
that has given up electrons to oxygen. So that means
that you have cobalt ions in a lattice like structure
on the cathode side. So that's the positive side of
your battery. Ah. But I hear you say. If electrons
are ditching lithium and they're heading over to the cobalt
(29:39):
side and joining cobalt ions, they are leaving behind lithium ions,
doesn't that ultimately become unsustainable because of the electric charges involved,
Because if electrons are joining positively charged cobalt ions, they're
eventually balancing out that charge. Right the electrons joined the
cobalt ion, they can't allout that positive charge. Meanwhile, you've
(30:02):
got lithium ions back behind on the anode side and
they have a positive charge wouldn't that just mean that
eventually the electrons would stop and feel less of a
pull towards the cobalt side and be pulled back towards
the lithium side. Well, that would happen, except the electrolyte
in between the anode and the cathode allows the lithium ions,
(30:23):
the possibly charged lithium ions, to cross over from the
anode side to the cathode side, and essentially the lithium
ions settle in between the layers of cobalt very much
in the same way that they had done when they
were lithium atoms over on the carbon side. The electrolyte
also prevents electrons from passing through it, Otherwise, again, batteries
(30:48):
would be useless because we would never convince those little
electron suckers to go through a circuit and do work
for us. In addition to the electrolyte, there's a non
conductive separator between the anode and the cathode because again,
you don't want them to come into contact with one another.
Uh So, there is a real good reason for this,
And just as a spoiler alert, I'll just say, boom
(31:09):
on the carbon side of the battery. You know, the
the anode side, you have a sheet of copper that
acts as a collector. On the cobalt side, you have
a sheet of aluminum to serve as the collector. The
positively charged lithium ions don't regain electrons in this process
when they come over to the cobalt side, so they
(31:30):
remain positively charged and they stay over there nestled in
the cobalt nets. But by moving the positive charge from
the annode to the cathode, the poll for the electrons
remains steady and the electron flow or electricity can continue
for as long as there are a sufficient number of
lithium atoms left on the anode side to give up electrons.
(31:51):
But once that amount gets depleted enough, then the battery
no longer has enough charge to allow electricity to flow.
During the recharging process, the source of electricity, whether it's
from a charging cable or docking station or wireless recharge
or whatever, it applies a voltage that's high enough to
reverse the flow of electrons so that now they will
(32:12):
move from the cathode side back over to the anode side.
The recharging process strips the electrons away from the cobalt,
so once again you have cobalt ions left behind. Sends
the electrons back over to the anode side, and the
positively charged lithium ions escape their intercalation with the cobalt
(32:32):
sheets they move back through the electrolyte over to the
anode side. This happens because the positively charged cobalt ions
and the positively charged lithium ions repel each other, but
the cobalts locked into place right, It's like a lattice,
so it can't really it can't move through the electrolyte.
The lithium ions are free to move across to the
(32:53):
other side, so they make the journey through the electrolyte
back over to the anode and they are reunite with
the electrons, and the lithium ions become lithium atoms, you know,
neutral charge. They rejoined with the electrons through the charging process.
Eventually you get to a point where you're back to
where you started, with an anode side filled with lithium
(33:15):
atoms and a cathode side filled with positively charged cobalt ions,
and then you can use the battery all over again. Now,
the layers I just described are not in a flat
plane in your typical lithium ion battery like it doesn't
look like a flat sandwich with a cobalt layer on
one side and a carbon layer on the other side
(33:35):
and electro light in the middle. No, Instead, these are
layers that then get folded over and over and over
again many times to maximize the energy density of the battery.
So if you could see through a battery case, you
would see what looks like tons of layers, it's actually
just really a very long series of layers that's just
(33:57):
been folded over itself many times. Now, if the anode
and cathode could touch one another, the chemical reaction would
accelerate rapidly and it would generate a lot of heat
in the process. This is what can lead to a
fire or an explosion, and it's why we have strict
rules about bringing lithium ion batteries on board planes. So
(34:18):
you might remember a few years ago when Samsung released
the Note seven smartphone, there were a few incidents of
batteries catching fire or even exploding, and it was a
big enough problem that Samsung recalled the Note seven on
two separate occasions, attempting to address the issue. According to Samsung,
there were two flaws in battery design that led to
(34:39):
this issue. The first battery, which came out from one manufacturer,
had two electrodes that were somewhat weak and prone to bending,
and that meant that if they bent in a certain way,
they might actually be in close proximity, in fact, close
enough to come in contact with one another, which created
a short circuit, which means the alli trunks could flow
(35:00):
through this shortcut rather than through and you know whatever
circuit they were supposed to go through, this being the
Note seven, and they would do so really quickly, and
that would heat the battery up beyond the failed point,
and you would have a fire or explosion. Now, the
second problem came after Samsung first recalled the Note seven
and replaced the batteries with a new one from a
(35:21):
totally different manufacturer. But this battery also had a design flaw,
a different one. Apparently, the welding on the new batteries
was defective and allowed for a similar short circuit issue
in the replacement batteries, So the Note seven handsets that
were supposedly fixed could still have a similar issue with
catching on fire or even exploding. These defects gave Samsung
(35:44):
a bit of a black eye. And it really spelled
doom for the Notes seven hand set. Those Samsung stressed
that the phone design itself was not at fault, it
was just really super bad luck with two different battery manufacturers.
You know, when we come back, I'm going to dive
into how fast charging works. But before I do that,
let's take another quick break. You know, one thing I
(36:12):
didn't cover before the break with lithium ion batteries is
that attached to the battery is special circuitry that can
control how much electricity flows into the battery during recharging. Uh.
It's sort as safety measure really and and this is
important that you can prevent a battery from overcharging, which
could damage the battery that could lead to one of
(36:34):
those short circuit scenarios and talked about. So you want
everything to be really controlled when you're recharging, to make
sure that the battery remains intact and you don't create
a dangerous situation or you know, just cause damage to
the battery which reduces its useful lifespan. So let's talk
a moment about USB cables only a little bit, because
(36:57):
that's just one of the ways that we can use
to charge a lot of electronics and it's one of
the ways that's compatible with some of the fast charging technologies.
If you listen to my recent tech glossary episodes, you
know that USB stands for Universal Serial Bus and it's
a type of connector and cable system, you know, ports
(37:17):
and connectors and cables that replaces a lot of other
ports and connectors and cables that we used to have
to rely on all the time to connect anything from
keyboards or computer amounts to computers or printers, all these
sort of things that we need to have all these
different proprietary cables for. It effectively helped replace those and
(37:38):
of course we find USB ports on all sorts of
gadgets beyond computers and smartphones. I've got a little shower
radio that recharges via USB, so it's on all sorts
of stuff, and the USB standard allows for the transmission
both of data and of power. But how much power
the USB cable can carry depend upon the type of
(38:01):
USB port and the type of cable itself, So you're
going to find that the amount of wattage or power
that a USB connection can carry is going to depend
on those ports and the cable being used. Essentially, you're
limited to whichever is capable of carrying the lowest amount
of power. So, while USB cables are largely backwards compatible
(38:24):
and USB ports are largely backwards compatible with cables, if
you're using an older cable connected to a later port,
you're gonna be limited to what that older cable can do,
even if the port is capable of greater things. That's
what I'm trying to get at here. So let's say
you're using a USB two point oh cable to connect
your phone to a charging block. Uh, the two point
(38:46):
oh standard has a maximum power output of two and
a half watts. That's five milliamps of current and five
volts of voltage, and you multiply those together you get
two point five watts. Fast charging technologs can recharge batteries
faster by allowing for greater wattage to flow into the battery. So,
(39:06):
for example, USB three point oh keeps the same five
volts as USB two point oh. All right, so the
voltage is the same from USB three point oh to
USB two point oh. However, USB three point oh can
carry a current of up to point nine apps. That
means you get a max power output of four and
a half watt's with USB three point oh. This tends
(39:29):
to be kind of the default wattage that gets delivered
via charging by USB USB three point one and three
point two. They include us B p D. P D
stands for power delivery that can support up to forty
eight volts, so a much higher voltage and up to
(39:51):
five amps, So that means you can have a maximum
power delivery of two forty watts. That's a huge leap
from four and a half what's obviously four and a
half to two forty UM USB four which is right
around the corner now, it will similarly support up to
two d forty watts of max power, but most devices
(40:13):
do not take advantage of this um, especially fast chargers, don't. Uh.
The max you see with fast charging right now tends
to be right around one hundred what's so not all
the way up to two forty What's like It's kind
of like anything where you think about about pressure, uh
(40:34):
and output, you get to a point where the pressure
and output will be too much to benefit from. It
would only be overwhelming or dangerous. So we don't see
fast charging really hitting that two forty what maximum at
least I'm not aware of one the ones I'm aware
of the fastest ones top out at one hundred watts.
(40:55):
So the USB C cables those are the ones that
have the well shaped reversible plug at the end, which
removes that annoying trade of having to figure out which
way is the right way up for your USB cable. Uh,
those are great if you happen to have stuff that
has USB ports on them, USB C ports on them,
(41:16):
and they have us B p D built into them.
So by default, most USB three point o ports just
push out that four and a half. What's so, even
if you do have a USB C cable the uh
it's you know, technically capable of delivering more power to
a device than four and a half. What's that's all
the juice you're gonna get if you have that cable
plugged into a standard USB three point o ports. So
(41:38):
again you're limited by the lowest output of whatever component
you're using as part of your setup. Now, if you're
curious about what kind of ports your computer has or
what kind of USB cables you have, you can always
look at the color inside the ports or inside the
connectors of those cables. If it's why eight, Well, you've
(42:01):
got yourself a relic that supports the old USB one
point oh standard. If it's black, it's USB two point oh.
A blue port is USB three point oh superspeed, and
if it's teal, that means you've got a USB three
point one superspeed or superspeed plush. And so that's true
(42:22):
with both cables and ports. If you've got both the
same color, then you know, all right, well, this is
at the highest that these two can support. Complicating matters
is that there are numerous fast charging technologies on the market,
and each of them has a different maximum power delivery rating.
Apple's fast charging tech is built on USB p D
(42:42):
and has a one what maximum power delivery So typically
you actually have to buy a fast charging cable and
charger because Apple does not usually include these in the
box with its products. Similarly, if you want to connect
via a lightning cable, you would need to make sure
that you had a lightning to USBC cable and that
(43:04):
it had USB p D compatibility built into it in
order to enjoy that fast charging capability. Apple's circuitry in
their devices like iPhones it monitors battery charge, so the
fast charging ability kicks in as long as the battery
capacity is measured at being below eight. Once the battery
(43:26):
reaches an eight charge, fast charging switches off and the
device will charge at the slower standard rate to avoid overcharging.
So this means if you run your iPhone until the
battery dies and then you use a fast charger, you
won't have to wait too long before you're at but
beyond that you'll see that charging has slowed down significantly.
(43:47):
Google also uses USB p D for its fast charging solution,
but Google's max power is significantly lower than Apples. The
Google fast charging tech maxes out at just a teen
what's compared to Apple's one hundred, so it delivers electricity
to devices with two amps of current at nine volts
(44:08):
of voltage. Like Apple, Google also limits fast charging two
devices that are below battery capacity. So if you have
a Google phone and an iPhone and they have comparable
battery capacities and you've both run them down to like power,
you plug your Apple phone into a fast charging Apple
(44:28):
station and your Google phone into a fast charging Google one,
you're going to see the iPhone recharge way faster, way earlier. Uh.
And so that's just how that works. Qualcom Quick Charge
is another popular fast charging standard and it has several
generations of that standard. So there's you know, quick Charge
(44:50):
one point oh, two point oh, three point oh, all
the way up to five point oh. If you were
recharging a device with first generation quick Charge, that being
quick Charge one point oh, you would be limited to
a maximum of ten watts of power. Quick Charge five
point oh, by contrast, can deliver one watts or more. However,
newer versions of quick charger really only found on a
(45:12):
few devices. Uh so it's you again. You're limited by
whatever the slowest component is. If that component is your
actual device, it doesn't matter how good a charger you
have or what cable you're using, You're going to be
limited by the max that device allows for. And in
this case, there just aren't that many devices out there
(45:33):
with quick Charge five point oh built into them. Quick
charge really does up the voltage. So, in other words,
this approach is all about increasing the pressure in the
system to charge batteries faster. Quick Charge five can allegedly
charge most phones from zero to capacity in just five minutes. Now,
I don't have a device that uses quick charge or
(45:55):
you know, the charging accessories I would need to do this,
so I can't test it. Myself, but that's what I've read.
If you go back to quick Charge three point oh
or earlier, you run into incompatibilities with us B p D.
But since quick Charge four point oh, quick charge accessories
work with USB p D accessories, so you can mix
and match cables and chargers from that point forward. Quick
(46:17):
Charge also includes circuitry that monitors the batteries temperature, and
it has automatic thermal balancing. Essentially, that means it's going
to use whichever charging method is going to keep the
coolest pathway to the battery to avoid overheating. Next, we've
got Samsung Adaptive Fast Charging. The latest version of this
(46:38):
supports max power of up to forty five watts in theory,
though in practice it appears that Samsung nerves this a
little bit. It tends to be a little under whatever
the max would be. Their version is also compatible with
us B p D, but limited again to forty five watts.
This fast charging tech is exclusive to Galaxy devices. Then
(46:59):
you've got mo roll a turbo Power. The most recent
turbo Power thirty product achieves a max power of twenty
eight and a half. What's that's built on top of
Quick Charge three point oh so you can kind of
think of this as a forked variation of quick charge technology.
Then you've got one plus warp charge, which is the
most recent version, supporting a max power of fifty what's
(47:23):
and the list goes on, and really all of these
different name brands and numbers gets confusing, and the fact
that there are so many different competing technologies for fast
charging means it's really hard to compare apples to apples,
and I don't mean technology that's coming from Apple in
this case. If you want to get really really basic,
(47:43):
you could argue that systems that supply a higher wattage
to batteries recharge those batteries more quickly. But that is
being a bit reductive because you have to consider all
the elements at play here. What are the limitations of
the accessories? What is the battery capable of accepting? Batteries
that have special circuitry in them to prevent them from
(48:04):
being damaged due to overcharging or voltage spikes? Are not
going to just allow unfettered recharging, So it's not like
you can just consistently up the wattage and decrease charging times.
It's not like you could Jerry rig A you know
five hundred what delivery system, and you recharge your phone
in a minute and a half, that would just most
(48:25):
likely lead to overcharging a battery and destroying it, or
the phone would just shut it down and limit how
much wattage could actually go to the battery in the
first place. So the process really has to be controlled
where else things get really dangerous really quickly. That being said,
the fact that there are so many different fast charging solutions,
and the fact that each of these continues to evolve separately,
(48:49):
means that it's really tricky to talk about fast charging
at all. If your phone is a couple of years old,
like mine is, it might be that you're maxed out
and an older version of whatever fast charge in tech
applies to your gadget, and that means that you would
have to upgrade to a newer device if you wanted
something that charged more quickly. And one other thing I
should mention. As your technology ages, you might notice that
(49:12):
it seems to drain battery life faster, that the battery
just doesn't last as long as it used to. There
are actually a few different reasons for this, some of
which play into the concept of planned obsolescence. That's a
strategy that companies use to create a planned life cycle
for products, partly in an effort to get you to
buy the next one of those things. But there are
(49:34):
some other things that play beyond just corporate strategy, and
one is that when you buy, say a smartphone, you're
locked into that hardware. You know, unless you are a
real d I Y tech head, your phone is pretty
much gonna stay exactly how it was when you bought it.
And yet the companies that created the operating systems, you know,
like Apple and Google, they're gonna keep evolving those systems
(49:57):
and releasing updates to the operating system them that allow
for more sophisticated and complicated apps. And these updates might
place a greater demand on older hardware, hardware that you know,
wasn't optimized for these newer versions of the operating system,
and as such, older handsets will see battery life suffer
(50:18):
because they're not optimized to handle that. In some cases,
companies will actually throttle processor speeds in an effort to
offset battery drain. The users tend to hate that too.
Write there's nothing like finding out the reason your phone
seems to be slower now is because the company that
makes your phone made it slower on purpose, Even if
(50:39):
that purpose was to give you more hours of battery life,
people hate that. Another reason battery performance declines over time
is that in the discharge and recharge cycles, there's typically
some build up of what's called solid electro light interphase.
This happens as lithium electrons and the electrolyte as well
as some organic so events react during the recharging phase
(51:03):
and it creates little build up deposits on the anode
side of the battery, which effectively locks down some of
the lithium in the battery. And because that lithium is
locked down, it means there's less lithium atoms to release electrons,
so it means your batteries max charge has diminished because
you don't have as much of the active ingredients if
you will. In addition, if you fully discharge a lithium
(51:26):
ion battery, some of that lithium will end up on
the cobalt side and form lithium oxide. Some of the
cobalt will form cobalt oxide, and effectively that removes the
lithium from the process and it locks it in at
that point, so you have reduced capacity because of that
as well, So you don't want to drain a lithium
ion battery all the way down to zero if you
(51:48):
can help it. Older rechargeable batteries had a similar issue
called the memory effect. This was prevalent back in the
nickel cadmium battery days. While it's generally a good idea
to recharge lithium ion batteries before they drop below say charge,
in order to avoid those lithium oxide build ups at
the cathode side, if it's a nickel cadmium battery, it
(52:11):
was a good idea to actually use them until they
were fully discharged. So of course that's led to some confusion,
right Some people are saying, well, should I wait until
my batteries all the way to zero before I recharge it?
Or do I wait until it's like at thirty and
recharge it. Well, with lithium ion, it's better to do
it and around thirty, but with nickel cadmium you wanted
(52:32):
to use that battery as much as possible because if
the batteries were not fully discharged before recharging, you could
see your battery capacity decrease. This is easier to understand
with an example So let's say I have an old
nickel cadmium battery and it's charged up to and I
run my electric podcast pruner until the battery gets down
(52:53):
to and then I recharged the battery back up to one. Well,
there's a chance that my nickel cadmium battery will behave
as if that charge was actually zero percent, and now
it will remember is really zero. So instead of having
a charge, I effectively have a seventy charge because it
(53:17):
will never go all the way down to zero again,
and it will get down to twenty five and then
the battery goes dead as if there were no charge
left in it. That was a problem with nickel cadmium batteries,
and it meant that you know, your battery charge would
severely decrease after a relatively short amount of time. Now,
as I said, that's not really the case with lithium
(53:38):
ion batteries, which tendency capacity reduce if you do run
the battery until it dies and then recharge. But even
if you use best practices, there will come a point
where a rechargeable battery will just outlive its usefulness. It
might take thousands and thousands of charge cycles before that happens,
but it will eventually happen. It's just a good idea
(53:58):
to practice good behaviors because that helps extend the useful
life of batteries as much as possible, which is a
good thing, just to avoid being wasteful. All right, that
wraps up this episode about batteries and fast recharging. I
know it's a big mess. I didn't get into too
much technical detail because really, when you boil it down,
it does get down to how much wattage do these
(54:19):
different methods apply to batteries and how fast can batteries
accept that? And at what point do these systems cut
off fast recharging to avoid overcharging a battery. That's really
what it it gets down to when you really dig down.
If you have any suggestions, like Perez did, thank you
again for your suggestion, you can send them to me
(54:43):
on Twitter. The handle for the show is text Stuff
H s W and I'll talk to you again really soon.
Text Stuff is an I Heart Radio production. For more
podcasts from my Heart Radio, visit the I Heart Radio app,
(55:03):
Apple Podcasts, or wherever you listen to your favorite shows.
H
Welcome to tech Stuff, a production from I Heart Radio.
Hey there, and welcome to tech Stuff. I'm your host,
Jonathan Strickland. I'm an executive producer with I Heart Radio
and I love all things tech and I end nearly
every episode of tech Stuff asking y'all if there are
(00:26):
any topics you'd like to hear me explain on the show.
And recently a lot of you have been sending in requests,
which is awesome, and I'm getting to those now that
those tech glossary episodes are all done. And first up
is a message from Brian Perez, who wants to know
about fast charging technology, which is a great and legitimately
(00:47):
confusing suggestion because there are a lot of different technologies
out there. So today we're gonna talk about how batteries work,
because that's important for us to understand this technology. Then
we're gonna talk more about how rechargeable batteries work, because
clearly that's going to be important. And then we'll talk
(01:08):
about what makes fast charging possible and some of the
different technologies that are out on the market and why
it's such a mess. Uh So let's do that, and
we'll start with the basics of electricity and that lovely
equation that tells us that wattage that that's a measurement
of power, is equal to current in ampiers times voltage
(01:33):
or volts, And it's good to remember the difference between
current and volts. Current refers to the amount of electric
current moving across a circuit, and voltage is the force
that drives that current. So frequently folks like me use
the analogy of water pressure to describe voltage and the
amount of water actually flowing through a system to describe current.
(01:57):
Uh So, voltage is sort of the umph at which
current gets pushed. We'll come back to the watch discussion
towards the end of this episode, because that's really at
the heart of fast charging technology. So let's talk about
how batteries work in general and the evolution of the battery. Now,
(02:17):
one thing we have to keep in mind is that
batteries don't create energy. Energy can be neither created nor destroyed.
Batteries store energy in the form of chemical energy. They
release energy in the form of electricity. So we're really
talking about converting one type of energy into another. That
(02:39):
is possible, right. We can't create or destroy energy, but
we can change it from one form to another. So
that's the heart of what batteries do. Batteries go through
an electro chemical reaction and through that process they release
electrons i eat. Electricity. The reaction takes play, and electrons
(03:01):
are a byproduct. They are released as part of this
chemical reaction. Even when a battery isn't being used, this
reaction can still occur, though typically at a very much
slower rate. Right otherwise, batteries would be dead before you
ever got a chance to use them, but it does happen.
This is called self discharge. This is one of the
(03:23):
factors that determines the shelf life of a battery. So
if you ever look at just a long list of
all the different types of batteries, you'll typically see the
listed you know, average shelf life of them, and if
it's a shorter shelf life, that tells you that there's
a higher rate of of self discharge. Generally speaking, that's
(03:44):
actually being a little too reductive because it also depends
on the capacity of the battery, like how how much
volume does the battery have, But we're not going to
dive too deep into all of that. So batteries that
are in hot environ ments also tend to self discharge
at a faster rate than batteries that are in a
colder environment, So you don't want your batteries to be
(04:07):
in someplace that's going to be really hot. However, this
also leads some people to make a decision that is
not very wise. It is not a good idea to shove,
you know, unused batteries in the freezer so that you
can make them last longer. The lower temperatures that the
batteries experience. That means that it will impede the chemical
(04:30):
reaction when you plug it into something. So this means
that a cold battery will not perform as well as
a normal battery until it gets up to temperature. And
when I say that the battery will eventually go dead
through self discharge, often we are talking about a factor
about years, right, So self discharge doesn't happen overnight. There's
(04:51):
no reason to put batteries into the fridge or the
freezer or anything like that, because you're likely going to
use them before they would have self discharged anyway. Setting
aside stories about you know, ancient Babylonian containers that might
have been used as some sort of proto battery, possibly
for the purposes of electro plating materials. The ancestor of
(05:15):
the modern battery really took shape in sevent with Alessandro Volta,
and his name gives us the word volt. More importantly,
our history starts with a disagreement between two scientific thinkers,
and those thinkers were Volta and Luigi Galvani. Now, Galvani
(05:36):
had observed in the seventeen eighties that if he were
to take a frog that was really most sincerely dead
and expose said dead froggy's leg muscles by you know,
cutting away the skin and then touching that muscle with
an arc made from iron and brass, it would cause
the muscle to twitch. Now, Galvani had already run experiments
(06:00):
using things like an electrostatic generator, so a device that
generates an electrostatic charge, and he knew that there was
some connection between muscular movement and electricity because of this.
But this was different, right because he was using what
appeared to be an inert pair of metals. It was
an iron embrass, and there was no electro static machine
(06:21):
generating a charge. He wasn't even doing this during a thunderstorm.
He had observed that thunderstorms could also produce electrostatic charges
that could then influence experiments like these, But this was
a case where neither of those things were components. So
he said, the electricity must reside within the muscle itself.
(06:41):
If it's not in the iron embrass, it's gotta be
in the muscle, and Volta thought that his buddy Galvani
was totally on the wrong track. Volta's assertion was that
the cause of the twitching was due to the use
of two different metals that were connecting to one another
through the medium of a moist conductive UH substance, that
(07:04):
being the froggy's leg muscle. So Volta decided to experiment
in the field of electrochemical reactions to see if perhaps
he was right and if Galvanni was wrong. So Galvanni,
by the way, was totally right in that muscle movements
are the result of electrochemical processes, but in this case
Volta was saying, yeah, but that's not what's happening here.
(07:26):
I don't think you're you're making the right hypothesis. So
Volta created a stack of material He alternated layers of
zinc UH. He then put in some cardboard that had
been soaked in brine, and then he would put on
layers of silver. So he kind of alternated with these,
and he was able to create a kind of proto
(07:46):
battery that we refer to with the charming name of
voltaic pile. There were some pretty big limitations to this, however.
The strength of this battery depended in part on the
number of layers that he could build up. However, he
couldn't make it too tall, because the layers on top
would start to press down so hard on the layers
(08:09):
below that the brine in that cardboard would get squeezed out,
and then it would suddenly be less effective. Also, the
metal would corrode fairly quickly due to the electrochemical reactions,
and uh, the the byproduct would build up on those plates,
and eventually they would impede the reaction from continuing, and
(08:32):
you'd see a decrease in electrical output because of it. Now,
just a few decades after Volta's work, there was an
English chemist named John Frederick Danielle who made an or Daniel.
I suppose it doesn't have an E at the end,
so I'll say daniel it's d A N I E
L l uh. He made an early battery using a
(08:54):
plate of copper, a plate of zinc, and some gnarly chemicals.
Let's see if I can paint a mental picture. So
he took a big glass jar and at the bottom
of the inside of this jar he put the copper plate,
so the copper plates at the bottom. On top of
the copper plate, he poured in a solution of copper sulfate.
(09:14):
By the way, these days, copper sulfate is used in
stuff like herbicides because it kills plants pretty darn effectively. Also,
when we're talking about batteries, were often talking about chemicals
that are acidic. That is pretty common. You've probably heard
about battery acid and it's one of the many reasons
why you don't want to mess around, you know, cutting
(09:36):
open batteries and stuff. There are a lot of reasons
for that, specifically when you get the things like lithium
ion batteries and um that's one of the many ones.
So then he then on top of this copper sulfate solution,
he poured in a zinc sulfate solution. Now, copper sulfate
has a greater density than zinc sulfate, so the copper
(09:57):
sulfate settled down at the bottom of the jar, and
the zinc sulfate floated to the top. You've probably seen
like mixtures of oil and water that do this kind
of thing. Daniel then suspended a zinc plate within these
zinc sulfate half of the jar. So imagine like a
hook that hooks over the side of the jar, and
hanging from that hook is a plate of zinc held
(10:20):
horizontal above the copper sulfate level. Right, So you've got
two separate levels here, and two separate sulfates uh to
each plate. He attached a conductive wire. And now we
need a bit of an anatomy lesson for batteries. So
let's consider your typical battery. Let's say that you just
(10:42):
if you happen to have a battery nearby, you can
even look at one and and kind of get the
lay of the land. So you've got two terminals with
your battery, Like if it's a double a battery, it's
on either end of the battery. Right. These are the
points of the batteries that connect to a circuit or
or a load. This is the pathway that electrons will
take where at some point along the way they will
(11:04):
presumably do some sort of work. So you've got a
positive terminal and you've got a negative terminal. You could
connect these two terminals directly to each other with conductive wire,
but that's not a great idea. That would lead to
the battery discharging very rapidly, and for some tymes of batteries,
that could be dangerous as the battery will heat up
(11:24):
from the rapid electrochemical reaction, potentially leading to combustion or explosion.
So not a good idea to do this. Attached to
the positive terminal inside the battery is the cathode. Connected
to the negative terminal inside the battery is the annode. Together,
these are the electrodes of the battery. There's a separator
(11:46):
that keeps those two electrodes from touching. Otherwise we would
have a very similar situation to what I was talking
about before, where you connect the two terminals with a
conductive wire, only in this case it would be internal
inside the battery as opposed to connect did through an
external wire. The separator does allow an electric charge to
flow between the two electrodes. Uh. There's also a medium
(12:08):
called the electrolyte that facilitates the flow of electric charge.
So during discharge, The anode reacts with the electrolyte and
experiences and oxidation reaction. Ions that is, atoms or molecules
that carry an electric charge from the electrolyte will react
with the anode and that produces a new compound between
(12:31):
the two and in this process also releases electrons. So
now we've got our supply of electrons popping over onto
the cathode side. The cathode goes through a reduction reaction
in which ions, electrons, and the cathode begin to form compounds.
This process takes in electrons while the process that the
anode generates electrons, but the separator keeps the electrons from
(12:54):
just rushing over from one side to the other. Right,
you would think, all right, if we've gotten excess of
electrons and like charge repels like, then the electrons don't
want to be next to each other, right, they'd rather
get to the other side, especially as that side grows
more positive because the electrons are negative and opposite charges attract.
But the separator prevents the electrons from doing this. They
(13:17):
can't get to that side unless you open a pathway
for them. That pathway is the circuit. So when you
open up a circuit. You create a circuit that goes
connects between these two electrodes. Now the electrons have a
way to get away from the negatively charged side of
the battery and head to the positive charged side of
the battery, and they will do that even if it
(13:39):
means they have to do some work along the way.
Thus we have batteries. So with Daniels battery, which we
call the Daniel cell, the wire connected to the zinc
plate served as the negative terminal. The wire attached to
the copper plate at the bottom of the jar was
the positive terminal. And the cell worked really well. But
because we're talking about liquid components here, it couldn't really
(14:01):
be used in any sort of application that the thing
would be moved around because it would just be slashing everywhere, right,
So it had to be stationary, and that really limited
what you could do with this kind of battery. A
few decades later brings us up to the eighteen sixties.
That's when George Leshan switched things up by making a
(14:22):
battery out of a porous pot. He took some crushed
manganese dioxide with a little bit of carbon in it,
and he used that as the cathode. He packed that
onto the inside of the porous pot. The annode was
a zinc rod that was actually kept separate from the pot.
So you had a pot on the inside of which
(14:43):
was this mixture of manganese dioxide and carbon, and then
you have this zinc rod. Then he leant put both
the pot and the zinc rod into another container filled
with ammonium chloride that acted as the electrolyte. Now, this
solution of amonium chloride seeped through the porous pot to
(15:03):
make contact with the cathode and that allowed the electrochemical
process to begin and the carbon rod that would also
be inserted into this Uh, this pot acted as a
collector for the electrons. So that's what you would use
to you know, direct the electrons outward to whatever circuit.
This type of battery saw widespread use in telegraph stations,
(15:26):
but still relied on a liquid electrolyte, and UH that
really made it unsuitable for stuff what moved around a lot,
so still not ideal. We would see all that change
thanks to the work of inventor Carl Gossner from Germany.
I originally put in my notes that he was a
German inventor, But now that I read that, it sounds
(15:49):
like he invented Germans, and I'm pretty sure they were
around before him. Anyway, Gassner made several improvements to batteries,
and that meant that they would be practical in many
of our applications. For one thing, Gastner had the bright
idea to use zinc as the container material for the
battery itself. So the body of the battery was made
out of zinc and it also served as the negative electrode,
(16:12):
so it was doing double duty. It was the container
and the negative electrode, so the actual body of the
battery served as one of the two electrodes the anode.
In case you're trying to keep these things straight. Inside
the battery, he put in a folded paper sack which
served as the separator, which kept the interior of the
zinc case separate from the electrolyte. For the cathode, he
(16:34):
used a mixture of manganese ox side and in the
middle of this he suspended a carbon rod, which again
acted as the electron collector. And later he would add
zinc chloride to the electrolyte because it reduced the rate
at which the electro light would corrode the zinc uh
of the case. It would It would then extend the
batteries useful life by slowing down that that process. But
(16:59):
the most important part of this invention was that Gasner's
battery is what we call a dry cell battery. It
was not full of sloshy liquid. Even though the electrolyte
was sort of a jelly liquid e kind of thing,
the rest of it was all dry. I meant that
you didn't have to worry about the battery components slash
galt all over the place, admit that you could invert
it and it would still work. It opened up a
(17:20):
lot of applications for batteries. In the eighteen nineties, the
National Carbon Company, a US based organization, developed the Columbia
dry cell battery, which was another improvement. They first started
making La Sanche batteries in the eighteen nineties, but again
those were wet cell batteries. An engineer at the company
(17:40):
named E. M. Jewitt created a one point five volt
dry cell battery and got the blessing from the company
to make a commercial version that they could actually sell.
So in eighteen nine six NCC began selling a one
and a half volt six inch long dry cell battery. Interestingly,
the National Car been Company would buy a fifty steak
(18:02):
in another company called the American Electrical Novelty and Manufacturing Company.
The battery making part of that company joined in CC
and together they became known as ever Ready, and much
later that company would change its name to Energizer, So
that one dates all the way back to the early
nineteen hundreds. All the batteries I mentioned so far are
(18:23):
what we call primary batteries. So a primary battery is
a one use battery. That means once the battery goes dead,
it's really most sincerely dead. It's not coming back because
we're talking about a different chemical component reacting with another
chemical component to produce electricity, and then you get by
(18:46):
products as well, and you eventually run low enough on
those initial chemical components that you're not getting enough juice
and there's no way to reverse that process. Right once
it turns into the byproducts, the battery has become a nert.
Now a few things that can that can happen to
make a battery less effective. One is that, as I mentioned,
(19:09):
you could have your chemical agents depleted in the battery,
So what you've got now is essentially a container just
filled with useless goop as a result of all these
electrochemical reactions taking place. Another is that whatever you're using
as an electron collector might get covered in deposits, and
that blocks the collector's ability to collect electrons. And so
(19:31):
you might still have some viable juice in the battery,
but because of this corrosion coding elements inside the battery,
it's not able to have that that process go effectively.
Corrosion is also an issue as well for the electrodes.
If you've ever had an old battery and something and
you've just seen this gross kind of build up on it,
(19:53):
that's often the corrosion I'm talking about. And all of
these things lead to a batteries and ability to produce current.
With primary batteries, there's really no way to reverse this process.
The electrochemical reactions will stop, and then you've got to
toss the battery. Primary batteries tend to be relatively inexpensive.
They also tend to have a fairly long shelf life,
(20:15):
but they're also wasteful. When we come back, we'll talk
about secondary batteries, also known as rechargeable batteries. But first,
let's take a quick break. When I was talking earlier
about the development of the battery, the last inventor I
(20:37):
mentioned was Carl Gassner, who invented the dry cell battery,
which was in but the rechargeable battery actually predates the
dry cell battery, and the person who generally gets the
credit for inventing them is Gaston Plante. No one invents
like Gaston or imprints like guests. Okay, I'll never mind.
(21:00):
In eighteen fifty nine, he created a lead acid battery
that you could actually recharge his batteries and ode was
made of a sheet of lead, and he used a
sheet of lead dioxide for the cathode, and he placed
a linen cloth between those two sheets. Then he rolled
this into a cone shaped spiral. He immersed this cone
(21:21):
in a solution of sulfuric acid, which is pretty dangerous stuff,
and the chemical reaction that resulted released electrons and boom,
you get yourself a battery. Gaston discovered that if he
applied a charge to this battery so that current flowed
into the battery, it would actually reverse the electrochemical reaction
that produced the electrons. This battery then had a way
(21:44):
to discharge and then recharge. In eighteen sixty he presented
a nine cell battery to the French Academy of Sciences,
and his peer Camille Alphonse for continued to work on
the invention and saw it actually become a commercial product.
Camille would later make improvements to this battery, including a
process that would increase the battery's capacity for storing electricity.
(22:07):
And we still use lead acid batteries today. It's the
type of battery you find in your typical internal combustion
engine vehicle. So your typical car that has an internal
combustion engine also has a lead acid battery. Now, I
mentioned that Gaston created a nine cell battery, and that
is something that we should chat about for just a moment.
Some batteries, like car batteries, consist of multiple cells that
(22:32):
connect to one another within the battery itself. So a
typical car battery would have six cells connected in series.
If you connect batteries in series, you increase the voltage
that those batteries produce. Now, remember, voltage is kind of
like pressure. That's how much umph is behind an electrical current,
(22:53):
but it's not a measure of the amount of current itself.
So you're not increasing the current by adding batteries or
mattery cells in series. You're increasing the voltage. If you
add them in parallel, it's different. But we're talking about
in series one after the other. So your typical lead
acid battery has cells that individually have a voltage of
(23:15):
two volts, but because they are connected in series, the
battery overall has a voltage of twelve volts. Right, you've
got six cells each two volts. You've got them in series,
so it multiplies the voltage to twelve. Most of your
typical household batteries, like double as, triple AS, C and
D batteries, those typically come in at one and a
(23:35):
half volts. But again, if you connect them in series,
you get more voltage. So a flashlight that has two
batteries connected in series is actually relying on three volts
for the voltage. Another thing we should touch on is
that because batteries convert chemical energy into electrical energy, there's
a fundamental limit as to how much juice a battery
(23:58):
can hold. That doesn't mean all batteries are equal. Depending
on the materials used to create that electrochemical reaction, you
can get more efficient and energy dense batteries. For example,
lead acid batteries don't really have great energy density, which
you typically measure either by comparing how much energy the
battery can store compared to that batteries mass, or how
(24:22):
much energy it can store compared to that batteries volume.
There are two different ways of looking at it. Alkaline batteries,
which make up a lot of the typical batteries we
use today, the non rechargeable primary batteries that we use today,
those are better from an energy density metric, meaning, based
on that batteries mass or volume, it can hold more
(24:45):
energy than a lead acid battery. But we also have
to keep in mind that these are much smaller than
lead acid batteries. The batteries power density and energy density
depend on the mass and volume of the battery and
the type of chemical components that make up the anode,
the cathode, and the electrolyte. So we're ultimately talking about
a chemical physical process that relies on a limited amount
(25:08):
of source material, like a limited amount of fuel, if
you will. So this means that it's very hard to
make longer lasting batteries based on what we have today,
unless you're making literally just larger batteries. You can't really
squeeze more out of physics. It's just you're you're hitting
the fundamental limits of what is possible in a chemical reaction. Now,
(25:33):
in tech, we've got Moore's law, which we generally interpret
as meaning that every two years or so, the processing
power or processing speed of computers tends to double. That's
the very you know, dumbed down version of Moore's law,
but that's kind of how we interpret it today. But
we do not see batteries on a similar trajectory, right.
(25:55):
We don't see batteries increase in capacity at the same
rate as we're seeing processing speed or processing power. This
is because the laws of physics don't really care if
we need better batteries, which puts pressure on electronics manufacturers
too really create ways to limit how much electricity gadgets
actually require as they operate. Not just electronics manufacturers, but
(26:19):
also you know, the companies that design things like operating systems.
In order to make batteries last longer. You can't just
build better batteries. That's that's that's a much slower process.
It means that you have to be smarter with how
much energy you try to access so barring some miraculous
(26:39):
alien technology, we're not likely to see astronomical improvements to
battery life, though there are people who are working on it.
It's just we're not likely to see giant leaps there.
So that means we just have to be smarter about
how our gadgets access power. Often when we're talking about
rechargeable batteries, we are thinking about bowl devices like smartphones, tablets,
(27:02):
laptops and handheld gaming systems and that kind of thing.
These devices almost exclusively today rely on lithium ion batteries. Now,
if you were able to look inside a battery, and
I urge you to never ever ever do this because
there is dangerous stuff in those batteries, but you would
see that the battery consists of layers of carbon graphite
(27:25):
and lithium on the anode side. This is on the
negative terminal side of the battery, and we refer to
the arrangement of lithium that's kind of nestled between lattices
of carbon graphite as intercalation. So they're intercalated between these layers.
You can think of like the carbon graphite as being
almost like a net and the little lithium atoms are
(27:47):
nestled inside between layers of this net. Lithium has three electrons,
and you might remember from basic science class that electrons
orbit the nucleus of an atom within certain energy shells,
and that only a specific number of electrons can inhabit
each shell. For for the shell that's closest to the nucleus,
you can only have two electrons. So that means that
(28:10):
each lithium atom has two electrons in that first energy shell,
and there's a single lonely electron that's orbiting the nucleus
in the next energy shell out from the nucleus. That
also means it's pretty easy for lithium to give up
that electron. It's not holding onto its super hard. That
means the lithium atom, when it lets go of this electron,
(28:32):
becomes an ion. It's a charged atom of lithium, a
positively charged one in this case, because it's given up
an electron which carries a negative charge, but it's held
onto all of its protons, which have positive charges. So
when a lithium ion battery connects to a circuit and
that circuit becomes complete, the outermost electrons in the lithium
(28:53):
atoms go through the pathway of the circuit and leave
the lithium atoms now ions behind and head towards the
positively charged cathode side of the battery. That's because the
electrons carry that negative charge and negative is attracted to positive,
and the lithium ions left behind they do have that
positive charge to them. That will become important in a second. Now,
(29:15):
the cathode is positively charged because there is cobalt there
that has given up electrons to oxygen. So that means
that you have cobalt ions in a lattice like structure
on the cathode side. So that's the positive side of
your battery. Ah. But I hear you say. If electrons
are ditching lithium and they're heading over to the cobalt
(29:39):
side and joining cobalt ions, they are leaving behind lithium ions,
doesn't that ultimately become unsustainable because of the electric charges involved,
Because if electrons are joining positively charged cobalt ions, they're
eventually balancing out that charge. Right the electrons joined the
cobalt ion, they can't allout that positive charge. Meanwhile, you've
(30:02):
got lithium ions back behind on the anode side and
they have a positive charge wouldn't that just mean that
eventually the electrons would stop and feel less of a
pull towards the cobalt side and be pulled back towards
the lithium side. Well, that would happen, except the electrolyte
in between the anode and the cathode allows the lithium ions,
(30:23):
the possibly charged lithium ions, to cross over from the
anode side to the cathode side, and essentially the lithium
ions settle in between the layers of cobalt very much
in the same way that they had done when they
were lithium atoms over on the carbon side. The electrolyte
also prevents electrons from passing through it, Otherwise, again, batteries
(30:48):
would be useless because we would never convince those little
electron suckers to go through a circuit and do work
for us. In addition to the electrolyte, there's a non
conductive separator between the anode and the cathode because again,
you don't want them to come into contact with one another.
Uh So, there is a real good reason for this,
And just as a spoiler alert, I'll just say, boom
(31:09):
on the carbon side of the battery. You know, the
the anode side, you have a sheet of copper that
acts as a collector. On the cobalt side, you have
a sheet of aluminum to serve as the collector. The
positively charged lithium ions don't regain electrons in this process
when they come over to the cobalt side, so they
(31:30):
remain positively charged and they stay over there nestled in
the cobalt nets. But by moving the positive charge from
the annode to the cathode, the poll for the electrons
remains steady and the electron flow or electricity can continue
for as long as there are a sufficient number of
lithium atoms left on the anode side to give up electrons.
(31:51):
But once that amount gets depleted enough, then the battery
no longer has enough charge to allow electricity to flow.
During the recharging process, the source of electricity, whether it's
from a charging cable or docking station or wireless recharge
or whatever, it applies a voltage that's high enough to
reverse the flow of electrons so that now they will
(32:12):
move from the cathode side back over to the anode side.
The recharging process strips the electrons away from the cobalt,
so once again you have cobalt ions left behind. Sends
the electrons back over to the anode side, and the
positively charged lithium ions escape their intercalation with the cobalt
(32:32):
sheets they move back through the electrolyte over to the
anode side. This happens because the positively charged cobalt ions
and the positively charged lithium ions repel each other, but
the cobalts locked into place right, It's like a lattice,
so it can't really it can't move through the electrolyte.
The lithium ions are free to move across to the
(32:53):
other side, so they make the journey through the electrolyte
back over to the anode and they are reunite with
the electrons, and the lithium ions become lithium atoms, you know,
neutral charge. They rejoined with the electrons through the charging process.
Eventually you get to a point where you're back to
where you started, with an anode side filled with lithium
(33:15):
atoms and a cathode side filled with positively charged cobalt ions,
and then you can use the battery all over again. Now,
the layers I just described are not in a flat
plane in your typical lithium ion battery like it doesn't
look like a flat sandwich with a cobalt layer on
one side and a carbon layer on the other side
(33:35):
and electro light in the middle. No, Instead, these are
layers that then get folded over and over and over
again many times to maximize the energy density of the battery.
So if you could see through a battery case, you
would see what looks like tons of layers, it's actually
just really a very long series of layers that's just
(33:57):
been folded over itself many times. Now, if the anode
and cathode could touch one another, the chemical reaction would
accelerate rapidly and it would generate a lot of heat
in the process. This is what can lead to a
fire or an explosion, and it's why we have strict
rules about bringing lithium ion batteries on board planes. So
(34:18):
you might remember a few years ago when Samsung released
the Note seven smartphone, there were a few incidents of
batteries catching fire or even exploding, and it was a
big enough problem that Samsung recalled the Note seven on
two separate occasions, attempting to address the issue. According to Samsung,
there were two flaws in battery design that led to
(34:39):
this issue. The first battery, which came out from one manufacturer,
had two electrodes that were somewhat weak and prone to bending,
and that meant that if they bent in a certain way,
they might actually be in close proximity, in fact, close
enough to come in contact with one another, which created
a short circuit, which means the alli trunks could flow
(35:00):
through this shortcut rather than through and you know whatever
circuit they were supposed to go through, this being the
Note seven, and they would do so really quickly, and
that would heat the battery up beyond the failed point,
and you would have a fire or explosion. Now, the
second problem came after Samsung first recalled the Note seven
and replaced the batteries with a new one from a
(35:21):
totally different manufacturer. But this battery also had a design flaw,
a different one. Apparently, the welding on the new batteries
was defective and allowed for a similar short circuit issue
in the replacement batteries, So the Note seven handsets that
were supposedly fixed could still have a similar issue with
catching on fire or even exploding. These defects gave Samsung
(35:44):
a bit of a black eye. And it really spelled
doom for the Notes seven hand set. Those Samsung stressed
that the phone design itself was not at fault, it
was just really super bad luck with two different battery manufacturers.
You know, when we come back, I'm going to dive
into how fast charging works. But before I do that,
let's take another quick break. You know, one thing I
(36:12):
didn't cover before the break with lithium ion batteries is
that attached to the battery is special circuitry that can
control how much electricity flows into the battery during recharging. Uh.
It's sort as safety measure really and and this is
important that you can prevent a battery from overcharging, which
could damage the battery that could lead to one of
(36:34):
those short circuit scenarios and talked about. So you want
everything to be really controlled when you're recharging, to make
sure that the battery remains intact and you don't create
a dangerous situation or you know, just cause damage to
the battery which reduces its useful lifespan. So let's talk
a moment about USB cables only a little bit, because
(36:57):
that's just one of the ways that we can use
to charge a lot of electronics and it's one of
the ways that's compatible with some of the fast charging technologies.
If you listen to my recent tech glossary episodes, you
know that USB stands for Universal Serial Bus and it's
a type of connector and cable system, you know, ports
(37:17):
and connectors and cables that replaces a lot of other
ports and connectors and cables that we used to have
to rely on all the time to connect anything from
keyboards or computer amounts to computers or printers, all these
sort of things that we need to have all these
different proprietary cables for. It effectively helped replace those and
(37:38):
of course we find USB ports on all sorts of
gadgets beyond computers and smartphones. I've got a little shower
radio that recharges via USB, so it's on all sorts
of stuff, and the USB standard allows for the transmission
both of data and of power. But how much power
the USB cable can carry depend upon the type of
(38:01):
USB port and the type of cable itself, So you're
going to find that the amount of wattage or power
that a USB connection can carry is going to depend
on those ports and the cable being used. Essentially, you're
limited to whichever is capable of carrying the lowest amount
of power. So, while USB cables are largely backwards compatible
(38:24):
and USB ports are largely backwards compatible with cables, if
you're using an older cable connected to a later port,
you're gonna be limited to what that older cable can do,
even if the port is capable of greater things. That's
what I'm trying to get at here. So let's say
you're using a USB two point oh cable to connect
your phone to a charging block. Uh, the two point
(38:46):
oh standard has a maximum power output of two and
a half watts. That's five milliamps of current and five
volts of voltage, and you multiply those together you get
two point five watts. Fast charging technologs can recharge batteries
faster by allowing for greater wattage to flow into the battery. So,
(39:06):
for example, USB three point oh keeps the same five
volts as USB two point oh. All right, so the
voltage is the same from USB three point oh to
USB two point oh. However, USB three point oh can
carry a current of up to point nine apps. That
means you get a max power output of four and
a half watt's with USB three point oh. This tends
(39:29):
to be kind of the default wattage that gets delivered
via charging by USB USB three point one and three
point two. They include us B p D. P D
stands for power delivery that can support up to forty
eight volts, so a much higher voltage and up to
(39:51):
five amps, So that means you can have a maximum
power delivery of two forty watts. That's a huge leap
from four and a half what's obviously four and a
half to two forty UM USB four which is right
around the corner now, it will similarly support up to
two d forty watts of max power, but most devices
(40:13):
do not take advantage of this um, especially fast chargers, don't. Uh.
The max you see with fast charging right now tends
to be right around one hundred what's so not all
the way up to two forty What's like It's kind
of like anything where you think about about pressure, uh
(40:34):
and output, you get to a point where the pressure
and output will be too much to benefit from. It
would only be overwhelming or dangerous. So we don't see
fast charging really hitting that two forty what maximum at
least I'm not aware of one the ones I'm aware
of the fastest ones top out at one hundred watts.
(40:55):
So the USB C cables those are the ones that
have the well shaped reversible plug at the end, which
removes that annoying trade of having to figure out which
way is the right way up for your USB cable. Uh,
those are great if you happen to have stuff that
has USB ports on them, USB C ports on them,
(41:16):
and they have us B p D built into them.
So by default, most USB three point o ports just
push out that four and a half. What's so, even
if you do have a USB C cable the uh
it's you know, technically capable of delivering more power to
a device than four and a half. What's that's all
the juice you're gonna get if you have that cable
plugged into a standard USB three point o ports. So
(41:38):
again you're limited by the lowest output of whatever component
you're using as part of your setup. Now, if you're
curious about what kind of ports your computer has or
what kind of USB cables you have, you can always
look at the color inside the ports or inside the
connectors of those cables. If it's why eight, Well, you've
(42:01):
got yourself a relic that supports the old USB one
point oh standard. If it's black, it's USB two point oh.
A blue port is USB three point oh superspeed, and
if it's teal, that means you've got a USB three
point one superspeed or superspeed plush. And so that's true
(42:22):
with both cables and ports. If you've got both the
same color, then you know, all right, well, this is
at the highest that these two can support. Complicating matters
is that there are numerous fast charging technologies on the market,
and each of them has a different maximum power delivery rating.
Apple's fast charging tech is built on USB p D
(42:42):
and has a one what maximum power delivery So typically
you actually have to buy a fast charging cable and
charger because Apple does not usually include these in the
box with its products. Similarly, if you want to connect
via a lightning cable, you would need to make sure
that you had a lightning to USBC cable and that
(43:04):
it had USB p D compatibility built into it in
order to enjoy that fast charging capability. Apple's circuitry in
their devices like iPhones it monitors battery charge, so the
fast charging ability kicks in as long as the battery
capacity is measured at being below eight. Once the battery
(43:26):
reaches an eight charge, fast charging switches off and the
device will charge at the slower standard rate to avoid overcharging.
So this means if you run your iPhone until the
battery dies and then you use a fast charger, you
won't have to wait too long before you're at but
beyond that you'll see that charging has slowed down significantly.
(43:47):
Google also uses USB p D for its fast charging solution,
but Google's max power is significantly lower than Apples. The
Google fast charging tech maxes out at just a teen
what's compared to Apple's one hundred, so it delivers electricity
to devices with two amps of current at nine volts
(44:08):
of voltage. Like Apple, Google also limits fast charging two
devices that are below battery capacity. So if you have
a Google phone and an iPhone and they have comparable
battery capacities and you've both run them down to like power,
you plug your Apple phone into a fast charging Apple
(44:28):
station and your Google phone into a fast charging Google one,
you're going to see the iPhone recharge way faster, way earlier. Uh.
And so that's just how that works. Qualcom Quick Charge
is another popular fast charging standard and it has several
generations of that standard. So there's you know, quick Charge
(44:50):
one point oh, two point oh, three point oh, all
the way up to five point oh. If you were
recharging a device with first generation quick Charge, that being
quick Charge one point oh, you would be limited to
a maximum of ten watts of power. Quick Charge five
point oh, by contrast, can deliver one watts or more. However,
newer versions of quick charger really only found on a
(45:12):
few devices. Uh so it's you again. You're limited by
whatever the slowest component is. If that component is your
actual device, it doesn't matter how good a charger you
have or what cable you're using, You're going to be
limited by the max that device allows for. And in
this case, there just aren't that many devices out there
(45:33):
with quick Charge five point oh built into them. Quick
charge really does up the voltage. So, in other words,
this approach is all about increasing the pressure in the
system to charge batteries faster. Quick Charge five can allegedly
charge most phones from zero to capacity in just five minutes. Now,
I don't have a device that uses quick charge or
(45:55):
you know, the charging accessories I would need to do this,
so I can't test it. Myself, but that's what I've read.
If you go back to quick Charge three point oh
or earlier, you run into incompatibilities with us B p D.
But since quick Charge four point oh, quick charge accessories
work with USB p D accessories, so you can mix
and match cables and chargers from that point forward. Quick
(46:17):
Charge also includes circuitry that monitors the batteries temperature, and
it has automatic thermal balancing. Essentially, that means it's going
to use whichever charging method is going to keep the
coolest pathway to the battery to avoid overheating. Next, we've
got Samsung Adaptive Fast Charging. The latest version of this
(46:38):
supports max power of up to forty five watts in theory,
though in practice it appears that Samsung nerves this a
little bit. It tends to be a little under whatever
the max would be. Their version is also compatible with
us B p D, but limited again to forty five watts.
This fast charging tech is exclusive to Galaxy devices. Then
(46:59):
you've got mo roll a turbo Power. The most recent
turbo Power thirty product achieves a max power of twenty
eight and a half. What's that's built on top of
Quick Charge three point oh so you can kind of
think of this as a forked variation of quick charge technology.
Then you've got one plus warp charge, which is the
most recent version, supporting a max power of fifty what's
(47:23):
and the list goes on, and really all of these
different name brands and numbers gets confusing, and the fact
that there are so many different competing technologies for fast
charging means it's really hard to compare apples to apples,
and I don't mean technology that's coming from Apple in
this case. If you want to get really really basic,
(47:43):
you could argue that systems that supply a higher wattage
to batteries recharge those batteries more quickly. But that is
being a bit reductive because you have to consider all
the elements at play here. What are the limitations of
the accessories? What is the battery capable of accepting? Batteries
that have special circuitry in them to prevent them from
(48:04):
being damaged due to overcharging or voltage spikes? Are not
going to just allow unfettered recharging, So it's not like
you can just consistently up the wattage and decrease charging times.
It's not like you could Jerry rig A you know
five hundred what delivery system, and you recharge your phone
in a minute and a half, that would just most
(48:25):
likely lead to overcharging a battery and destroying it, or
the phone would just shut it down and limit how
much wattage could actually go to the battery in the
first place. So the process really has to be controlled
where else things get really dangerous really quickly. That being said,
the fact that there are so many different fast charging solutions,
and the fact that each of these continues to evolve separately,
(48:49):
means that it's really tricky to talk about fast charging
at all. If your phone is a couple of years old,
like mine is, it might be that you're maxed out
and an older version of whatever fast charge in tech
applies to your gadget, and that means that you would
have to upgrade to a newer device if you wanted
something that charged more quickly. And one other thing I
should mention. As your technology ages, you might notice that
(49:12):
it seems to drain battery life faster, that the battery
just doesn't last as long as it used to. There
are actually a few different reasons for this, some of
which play into the concept of planned obsolescence. That's a
strategy that companies use to create a planned life cycle
for products, partly in an effort to get you to
buy the next one of those things. But there are
(49:34):
some other things that play beyond just corporate strategy, and
one is that when you buy, say a smartphone, you're
locked into that hardware. You know, unless you are a
real d I Y tech head, your phone is pretty
much gonna stay exactly how it was when you bought it.
And yet the companies that created the operating systems, you know,
like Apple and Google, they're gonna keep evolving those systems
(49:57):
and releasing updates to the operating system them that allow
for more sophisticated and complicated apps. And these updates might
place a greater demand on older hardware, hardware that you know,
wasn't optimized for these newer versions of the operating system,
and as such, older handsets will see battery life suffer
(50:18):
because they're not optimized to handle that. In some cases,
companies will actually throttle processor speeds in an effort to
offset battery drain. The users tend to hate that too.
Write there's nothing like finding out the reason your phone
seems to be slower now is because the company that
makes your phone made it slower on purpose, Even if
(50:39):
that purpose was to give you more hours of battery life,
people hate that. Another reason battery performance declines over time
is that in the discharge and recharge cycles, there's typically
some build up of what's called solid electro light interphase.
This happens as lithium electrons and the electrolyte as well
as some organic so events react during the recharging phase
(51:03):
and it creates little build up deposits on the anode
side of the battery, which effectively locks down some of
the lithium in the battery. And because that lithium is
locked down, it means there's less lithium atoms to release electrons,
so it means your batteries max charge has diminished because
you don't have as much of the active ingredients if
you will. In addition, if you fully discharge a lithium
(51:26):
ion battery, some of that lithium will end up on
the cobalt side and form lithium oxide. Some of the
cobalt will form cobalt oxide, and effectively that removes the
lithium from the process and it locks it in at
that point, so you have reduced capacity because of that
as well, So you don't want to drain a lithium
ion battery all the way down to zero if you
(51:48):
can help it. Older rechargeable batteries had a similar issue
called the memory effect. This was prevalent back in the
nickel cadmium battery days. While it's generally a good idea
to recharge lithium ion batteries before they drop below say charge,
in order to avoid those lithium oxide build ups at
the cathode side, if it's a nickel cadmium battery, it
(52:11):
was a good idea to actually use them until they
were fully discharged. So of course that's led to some confusion,
right Some people are saying, well, should I wait until
my batteries all the way to zero before I recharge it?
Or do I wait until it's like at thirty and
recharge it. Well, with lithium ion, it's better to do
it and around thirty, but with nickel cadmium you wanted
(52:32):
to use that battery as much as possible because if
the batteries were not fully discharged before recharging, you could
see your battery capacity decrease. This is easier to understand
with an example So let's say I have an old
nickel cadmium battery and it's charged up to and I
run my electric podcast pruner until the battery gets down
(52:53):
to and then I recharged the battery back up to one. Well,
there's a chance that my nickel cadmium battery will behave
as if that charge was actually zero percent, and now
it will remember is really zero. So instead of having
a charge, I effectively have a seventy charge because it
(53:17):
will never go all the way down to zero again,
and it will get down to twenty five and then
the battery goes dead as if there were no charge
left in it. That was a problem with nickel cadmium batteries,
and it meant that you know, your battery charge would
severely decrease after a relatively short amount of time. Now,
as I said, that's not really the case with lithium
(53:38):
ion batteries, which tendency capacity reduce if you do run
the battery until it dies and then recharge. But even
if you use best practices, there will come a point
where a rechargeable battery will just outlive its usefulness. It
might take thousands and thousands of charge cycles before that happens,
but it will eventually happen. It's just a good idea
(53:58):
to practice good behaviors because that helps extend the useful
life of batteries as much as possible, which is a
good thing, just to avoid being wasteful. All right, that
wraps up this episode about batteries and fast recharging. I
know it's a big mess. I didn't get into too
much technical detail because really, when you boil it down,
it does get down to how much wattage do these
(54:19):
different methods apply to batteries and how fast can batteries
accept that? And at what point do these systems cut
off fast recharging to avoid overcharging a battery. That's really
what it it gets down to when you really dig down.
If you have any suggestions, like Perez did, thank you
again for your suggestion, you can send them to me
(54:43):
on Twitter. The handle for the show is text Stuff
H s W and I'll talk to you again really soon.
Text Stuff is an I Heart Radio production. For more
podcasts from my Heart Radio, visit the I Heart Radio app,
(55:03):
Apple Podcasts, or wherever you listen to your favorite shows.
H
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