Inside an iPhone Battery Factory – in China

Today we’re gonna find out how iPhone batteries are made from start to finish. I’m here at the Pisen battery factory in Shenzhen, China They make aftermarket replacement batteries for iPhones like this one. They also make tons of other types of batteries They aren’t sponsoring this video But I’m thankful to them for letting us in on short notice so I can show you how cool it is First, we’re gonna head off to their battery cell supplier in Dongguan two hours from here Very simply, lithium-ion batteries are made out of two sheets of aluminum, a cathode and an anode coated with two different substances On the positive side the cathode is lithium cobalt oxide, and on the anode side, the negative side, is graphite There are two identical factory lines here for adding that coating on the aluminum sheet This is the cathode side where the lithium is, these giant mixers behind me are mixing the lithium cobalt oxide With a binding agent and a conductive agent, and they’re sort of like big stand mixers that you would find in your kitchen for making cookies or bread or cake Once they’re fully mixed these drums underneath are wheeled over and Then they pump the solution out through this pump here and through this pipe into the next room where they’re coating the aluminum sheets So let’s go take a look So this is that pipe coming from the pump all the way over here To this filter and this is where it’s actually getting coated on the aluminum sheet So the aluminum sheet starts out on this roll here This is actually the second time this particular sheet is being coated, they coat both sides, but the first pass looks exactly like this They just happen to be running this right now. That sheet goes through a series of tensioning rollers Underneath this platform, up over here and around this drum where the actual coating is happening So right here, there’s two plates where the solution of lithium cobalt is being squirted out very precisely Onto the sheet as consistently as they can. The next step is to bake it on with a giant conveyor belt oven Let’s go see that So through here we could actually see the anode line and I misspoke before, I said that both sides were aluminum This is actually copper. This giant oven runs all the way from this wall All the way down to that wall all the way down there, and it has eight different temperature controlled sections, where it gradually brings that aluminum material up to temperature And then gradually cools it off, and it ends on the other side of that wall. Let’s go see Phew, it is hot in there The next step is inspection. There’s a lot of inspection in making high quality batteries This is an x-ray inspector that inspects for a perfectly even coating on the backing material and it’s got an x-ray head that’s moving back and forth across the The panels as they go through. And finally, it goes over here and gets wound on this drum. Next, We want to make this cathode layer as thin as possible this is an 800 ton rolling press that has two rollers that smash the cathode and The cathode coating as thin as possible. It’s shut down right now They’re waiting on further up the line to reload a roll but uh But this would normally be feeding through the press here then through a thickness gauge and again onto a roll where it’s gonna go upstairs And we’ll put together the actual battery cells. Let’s go see that All right. Next we’re going into the cleaner parts of the factory. We gotta go through an air shower and then switch clothes That just knocks off all the dust So this is the anode slicing workshop and this machine here takes a full roll of material This is the anode side but a cathode I imagine is pretty similar takes the full width roll that we saw downstairs and Slices it into thinner rolls that are the right width to make a battery. The other thing that’s going on here Is CCD inspection aka visual inspection with a camera, checking the top and bottom just for any visually obvious imperfections in the coating layer that might be a problem and it’ll actually stick a sticker on here that will be cut out to mark a bad suction that will Be cut out later in the process let’s head into the process that I have been most wanting to see which is where they actually take this and turn it into a Battery cell. Now it’s time to change into a full cover-all for the next part Which is supposed to be very clean. We’ve got Mr. Jang here from the factory with us And then Tony who’s been translating for me? Yeah. Okay. So we got to take this all the way off. Alright? Alright, let’s do that. We’ll be back in a minute. Tada I want to show you one thing real quick before we go to the next step That’s as far as I could bend over because this part is too short. Let’s go Oh! Wow Okay, this is easily the coolest machine I have ever seen in any Factory. This is where the magic happens Okay, so it’s gonna take me a while to figure all this out it looks like we’ve got the anode material down here, that copper colored material. And then the

Cathode material is over here and there’s a whole bunch of tensioning going on But the magic is happening right here This is where that actual- the two layers are coming together With an insulator in between and are being wrapped up into that jelly roll, right? This is a spiral of two materials sandwiched together; the insulator in the middle and then somewhere down the line We’re injecting that electrolyte. Let’s see if we can get Mr. Jang in here to explain some more of the details. So Mr Jang, I want to understand a little bit more, it seems like the heart of the operation Is right here where we’re wrapping the cathode there and the anode over there and the insulation material here into that jelly roll sandwich But there is a ton of Machinery on both sides Can you explain a little bit about why this is so complex? And then what is the green stuff here? It looks like tape? And is that the section in between two pieces of tape? That’s the the length of one battery? one cell? So like from here to here is one cell? So not very long, only about that long? Yes I noticed there’s a ton of blue stuff in here Is that the same thing we’ve been walking on on the ground? And there is just layers of this blue tape all throughout this machine trying to capture dust I’m beginning to think that dust is very important to keep this as clean as possible Everywhere we go, it’s all about dust dust dust. No dust So this is where the battery tabs are being cut and attached This is the roll of battery tabs here. And then it’s a metal strip that’s feeding in here. And then this is the cutter There. It cuts it off and then it’s coming over here and sticking it on to the anode, the negative side right there That is super cool. So this is tape that Mr. Jang was talking about And it looks like it’s got two spools, one for the top and bottom, and it’s sticking on One at a time. Check this out there it goes, there’s one piece, stick it second piece Stick it. Ah There’s the top. Here’s the bottom. It’s sucking the tape upside down To a vacuum head. Can you hear this in my microphone? Wait for it [Tape Unspooling Noise] That’s really cool So this part mainly is like, Packaging. Like packing all of the cells Into the aluminium (Scotty) Putting the outside on? Yeah. The outside layer. So that looks like what’s happening over here Right here is where we put it into the packaging. What is the outside made out of? Aluminium Aluminium, okay. So an aluminium package on the outside, and Heat sealed? Yeah, heat sealed So we got the rolls here of the anode and cathode, and the insulation material Put those in the outer package here with this really complex line That’s basically just creating a vacuum pack right? a sandwich. And heat sealing it And then down here is where we’re putting in the electrolyte? Yeah injection. Yep Electrolyte will be injected. And that’s right here right? That’s the electrolyte right there? That’s right. And then the box at the back is the vacuum Yep. Yeah, and that’s sucking out all the air and excess gas and whatnot. Let’s look at the finished product down here Can we pick one of these up? I need gloves. Okay, this factory line is amazing I’ve not seen anything quite this automated before. It is impressive [Machine plays short tune] It also sings songs I’m assuming for various air conditions I want to show every last little pulley, but we’re gonna have to show it at a little bit higher level

Okay. So this is now starting to look like a battery cell. So this is the cell here, right? And this will be cut off. Yep. And what are these two lumps here? Oh, this is the air bubble. Oh! okay, so that was all the air that was in here before, that got pushed into those Ah, I got it. And then of course, these are the two battery tabs these, we’ll see later will be attached to the rest of the Electronics on the battery. And then just a little bit of protective plastic here. Yep. That’s the protective layer, yeah Okay, and then this whole section will get sliced off later in the process, right? Yes. Yeah, okay. All right I did a little research ahead of time. We walked around earlier off-camera. Let’s go see what happens next now We finally got to change out of our bunny suits Back in the hallway outside the labs. The batteries next come in here into this warm room. It’s 44 degrees Celsius That’s about, I don’t know 110 Fahrenheit, somewhere in there. They sit here for 48 hours and they age before they get charged Let’s go take a look at the charging process. You got to do the first charge while you’re physically squeezing the battery and Mr. Jang said that this is because if you don’t the battery gets like squishy and fluffy, and so you want to press it together So it’s nice and firm on that first charge. So here they’ve basically got a charging setup That’s also a press that’s pressing all the batteries together. And he said that it’s really important This machine in particular is designed. So that there’s constant pressure on all the batteries, so that one isn’t, You know, firmer than the other. There’s a robot arm over here that’s loading batteries off a stack, and then this robot here is Unloading batteries that are finished charging out of the press Mr. Jang said that they charge batteries for two hours This first time. They take two hours to charge the batteries up to 50%, And that’s all they charge them to at this step The next step is to cut off all this excess material so that it looks like a normal battery But there’s a little bit of complication. These two bubbles here are pockets of gas; carbon dioxide And we need to puncture those and then suck out all of the excess gas under a vacuum and then heat seal this This piece here. And then finally trim it off. This is the phase where it’s loading the vacuum chambers. There’s three vacuum chambers here They puncture holes in those little gas pockets and then heat seal the seam And then the batteries come down here, and this is the trimming and folding setup So they trim off that excess and then fold it over and finally they get repacked again. Now, it’s time for some serious charging So the batteries are now at 50% charge But we got to bring them all the way up to 100% and then discharge them to see what their actual capacity is So that’s what’s going on in here These are a bunch of shelves that all have the batteries hooked up to their own individual clips, positive and negative The clips are actually kind of special, they have a giant padded back. That’s where the actual charge or discharge Current is happening. Then they have a little voltage sense pad up front and that gives an accurate voltage measurement while they’re charging or discharging So all these are hooked up, this process, they come by and hook these up by hand This process takes about seven hours to charge it all the way to 100% Down to zero and then bring them back up to 50% And that gives a pretty good accuracy of what is the actual capacity of each battery They have this little data grid two dimensional QR code here. That’s for tracking each individual battery through this process They’re starting to accumulate data now about the quality of each battery Kenneth is off camera talking crap and saying that it’s a data matrix not a data grid, and that it’s not a QR code I’m just gonna call them QR codes from now on and the last main step Is another aging process to just check that the batteries are stable. So the very first thing they do is check the voltage again They then put them in storage for five days So the first three days are high temperature, the second two days are normal temperature Then they check the voltage again down here and do a bunch more inspection, so camera inspection X-ray inspection, just checking quality, consistency, and making sure that everything is as they expect Next let’s head over to Pisen’s factory in Shenzhen to see how they turn these battery cells into fully fledged iPhone batteries This is a pallet of battery cells. They’re all packed into little trays here, but they’re not a finished product yet They’re just the battery itself. We need to add a bunch more before they’re ready to ship out The next step is to print on the logo and all of the warning information And labeling and recycling info and things like that all the labels that go on here The only thing was printed on here prior was just this little tiny QR code They’re using a silk screening process with UV curable ink and that’s just so that it dries Instantaneously because they want to be able to print on both sides so they don’t want to have to wait for it to dry So the first step here is the silk screening they’ve got their design here on the silk screen just like a t-shirt silk screen and the batteries underneath and then Under door number two. We have the UV lamp, which is curing the UV paint. And in door number three is the real surprise They have a robotic set of pincers that’s flipping it over so they can print the other side and then back here

This guy’s job is QA So he’s checking every single battery on both sides to make sure that the printing is correct He doesn’t have any smudges or anything like that. It looks like he could do this in his sleep The next step is we need to attach the battery management system the BMS onto the cell like this, and the battery management system is all kind of the smarts that Pisen develops here. This is the the system that protects against over voltage over current Discharging the battery too much. It’s the safety system for the battery It’s also what’s called the gas gauge, which is literally what it sounds like It keeps track of the charge on the battery by watching what goes in and what goes out, what goes out and what goes in Let’s check this out. This is a super awesome automated line I asked them if you could buy one of these but they said no this is totally custom. They designed it they had somebody else build it but wait till you see the First step is just loading the trays. So we’re just loading batteries on to the conveyor belt In here, this is where we’re doing the trimming So we’re flattening and then they’re coming in and cutting and then they’re bending them over each Stage as this rotates does one more thing one more thing one more thing. This machine looks like an erector set It’s all you know channel stock aluminum All of these parts are pretty standard for factory machines and you kind of glue them together in different ways to do whatever you need It to do Some of the things that here are just ingenious and and so simple yet do something that ends up being super complex So this is the part where we’re actually attaching the BMS onto the battery And they’re using a fiber laser If you guys haven’t seen the fiber laser video we did up in Jinan go check that out up here It’s pretty darn cool. This is a much smaller one than we showed in that video. Same idea though We’re using a fiber laser to weld the pieces. I think this is steel. Yeah one is aluminum and the other one, Not sure I don’t know, let me find it. I don’t even know where to find it. Oh, okay Nickel nickel nickel. Okay, I know nickel. Yeah, you know, okay. So one side is aluminum one side is nickel. Yeah. Yeah So soldering is out of the question here. We cannot solder this. You must weld us. Yes. You must weld it okay Got it. All right, so nickel and aluminum And that’s why we got a laser. Oh, so the battery management systems come from a tray over there Batteries are coming in from over here we’re lasering each one, putting them in a jig and lasering each one to join them together and then Flipping them over onto a conveyor belt to the next step. So Mr. Yang I wanted to ask you I saw that you have a little box of sand here with some tongs And a bucket of water with some scoops and I wanted to ask you what are all these for? So this is if a battery catches fire, and you need to put it out. Yes I got it. Yeah. Yeah, so you have long tongs to reach into the machine to get it and put it out. Yeah Got it. How often does that happen? (Translator) That could happen like twice a day Twice a day!? Oh my god, that sounds exciting! Yeah, I don’t want it to happen. Right? No, I understand I wouldn’t want it to happen on my machine either. Yeah So the next step now that the BMS is attached is bending it into the right orientation That’s what this machine does, at least what’s happening here. Mr. Yang, There, this machine here. What does that do? I can’t see, it doesn’t look like it’s doing anything Right, but that’s what this is doing. What about that one? (Translator) So this is for insulation, this part, but at the moment, because they have a part that has to be installed,

So at the moment they can’t- Oh, it’s just broken? It’s broken, Yeah Yeah, okay The function is to insulate. So they’ve got women doing it by hand right now? Yeah. Okay. I got it. Oh, I see. Okay, so Here he’s adding more complex bends to the cable where it plugs into the iPhone There’s some extra crimps So these here are totally flat and he’s adding all the necessary bends on this So that it fits into the iPhone in the right orientation And then they’re just putting tape to insulate, is that right? Yes. Yeah, there is another half-manual, like an auto machine. Yeah, so they they put it there, And then they bring it over. And that’s just putting this yellow cap on? I see Yeah, so there’s some tape and stickers being put on, on the machine over here, okay So we got stickers going on here And then we got another turntable. Let’s figure out what this turntable does so batteries are coming in over here, getting loaded by this one and Then tape being put around folded down Being put on the conveyor belt back over there, and she is checking that every one is correct, and fixing them if they’re not One by one. This one is not working today? Is that right? Yeah, but this is normally the machine that checks to see if there’s any Like liquid leaking from the battery? Yes. They told me this earlier off-camera Okay, so let’s go ahead and we’ll go to the next step So some of the steps are being worked around with people right now. Batteries are coming off the line here Then, You guys told me earlier. My understanding is that the batteries now sit for 72 hours. Is that right? Yeah, why are they sitting? Oh, to see if any liquid comes out. Leaking, okay. Yeah So to see if it’s been punctured. Like there’s a hole in it. That’s right and then also, there’s checking the Internal resistance. Right. Whether there’s a bad quality one that has high resistance, so they have to throw it out Okay, so they sit for 72 hours in a storeroom. Yeah, and then they come out here for testing, right Let’s go look at that next. I just want to add as an aside We came through earlier with some of the higher managers and I got kind of an overview of the process So I’m not explaining this to Mr. Yang. He totally knows what’s going on. I’m just making sure that my memory is correct So I’m not saying the wrong stuff. Okay, so we’re testing voltage and impedance Just basic battery testing So these machines here, these testing machines, are these machines that Pisen made, or from someone else? Third-party, yeah Yeah, and they, what are they testing, because, he’s testing voltage What are these guys testing? Okay, so we’re making sure that the batteries are compatible with an iPhone and that they can be read by the iPhone Is that right? Yes. So the iPhone can talk to the battery management system to see how much charge is there, What is the current flowing? Serial numbers, manufacturer information, things like that. There are a lot of people testing here, plugging in one battery at a time Here we are at the last stage of the process. We’ve got batteries ready to go to the customer We’ve got to put them in boxes. So over here, we’ve got trays, plastic trays, that go inside the box She’s adding the battery strips that you need to add them to your phone putting the batteries in those trays putting them on the line and there’s a Cover piece of plastic that goes on top before it goes into the box. This right here is quite cool So this is a camera that’s taking a picture of the QR code so that they know what battery went into what box there’s a QR code on the outside of the battery and Somewhere down the line here, they are then scanning that and matching the two together. Got boxes, ready to go here There’s the QR code, each one of these barcodes is unique So they know, they can differentiate every single battery from each other. This machine, is literally opening the box oh, here’s the barcode scanner right here and then stuffing the battery in. How cool is that But this. This beats everything. This is an automatic box closer It’s flipping over the flap on the bottom and tucking it in. Next is my other favorite machine This is the sticker machine! This is putting those little clear dots of adhesive, of sticker Over the bottom flap to keep it closed. They’re on the roll here They’re really hard to see, but there are little circles here. They’re coming They’re being flipped down on here And then this brush is sweeping down over them to stick the bottom part right here on. Then finally,

This is printing the manufacturing date. So there’s a little black Printing here, that just says when it was manufactured, what batch, that kind of thing And then finally we go into the shrink-wrap machine and this is just adding the shrink wrap on the outside of the box I don’t quite why they do this because it’s not over the top and bottom flap But my guess is that it keeps the artwork on the box looking nicer. Finally, We take the little boxes and we put them in medium boxes, and then we put the medium boxes in big boxes and of course they’re scanning barcodes all along the way so that they know what went where And finally, we have a finished product ready to put on a shelf Lastly, I just wanted to quickly show you their testing lab, their quality control Facility where they test new batteries, test quality of batches And one of the things they do in here is do temperature and humidity testing Just to make sure that the batteries don’t do anything scary when they heat them up or there’s really high humidity so this is a humidity and temperature testing chamber. Over here, They’re doing real-world device testing so they’re taking those iPhone batteries and they’re putting them in an actual iPhone and Seeing how long it takes to discharge so they can they can accurately say it lasts for 10 hours, it lasts for 12 hours. Whatever The really cool part is that this is a webcam pointed at the battery display here So they are actually Videoing This battery as it as it decreases, so they know the exact moment that it hits zero. And so they’ve got an iPhone here They’ve got a couple more iPhones here. They had an iPad out earlier when we came through the first time. Super cool So here they have a spectrometer for RoHS testing R-o-H-S, which is the environmental standards around what elements can be in whatever product you’re producing. The most important one is lead So lead-free solder, things like that. They’re testing The various parts that go into the batteries here to make sure they conform to those standards. In here, They have all the really crazy tests so here This is a salt mist test they’re spraying salt water all over the battery to make sure that it doesn’t short out and… blow up Over here they have a furnace. A blast furnace So they are a furnace that controls blasts So they are cooking the batteries up to 130 degrees Celsius (266° F) To see if they puff up but don’t explode you know the biggest concern that consumers have with LiPo’s is, you know, they catch fire, right? The famous, you know Samsung Note 7 catching fire on airplanes and causing all sorts of problems This is them testing to make sure that that doesn’t happen with their batteries and that they’re safe to you know, within the limits That are reasonably gonna happen. It’s good to know They’re paying attention to it so that we don’t have to. That about does it for this time. I’m Scotty from Strange Parts This is Pisen I want to thank them for giving me access to their factory If you want to find out more, click the link down in the description, but for now make sure you hit that subscribe button So you don’t miss more factory tours. I’ll see you again soon