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 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 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 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 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. 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, 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 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 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 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 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 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 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 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 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 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 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 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. 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 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. 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 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 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 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 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. 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 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 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 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 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 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 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 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 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 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 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 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 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 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 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 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 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, 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 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, 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 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 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 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 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 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 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 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, 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 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, 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, 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 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. 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 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 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. 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 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, 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 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 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 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 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 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 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, 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. 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 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 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, 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 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 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 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, 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 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, 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 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 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, 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 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 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 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. 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 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 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 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 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 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 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 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 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 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 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 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 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 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 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 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 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 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 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 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, 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 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 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 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 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. 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, 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 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 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 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 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 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 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. 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 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 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 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 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 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 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 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 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 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 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, 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 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 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, 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 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 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 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 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 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 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 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 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 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 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 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 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 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 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 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 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, Apple Podcasts, or wherever you listen to your favorite shows. H