 Like many of you, we've spent a lot of money on batteries over the years. These red bricks for our cameras, for example, cost a whopping $350 a pop. But that isn't even the biggest problem with them. You see, even rechargeable lithium batteries are consumable in a sense. After a few years of regular use, this guy right here gets us a whopping 20 minutes of battery life. And that's on a good day. Which got us thinking. The housing's still fine. The battery management system, or BMS, which handles charging and safety, that's fine too. So would anything prevent us from just swapping out the tired cells inside, saving us some money and keeping needless e-waste out of the landfill? Well, you've already seen the title of the video, so I think you know the answer to that. But what you don't know is just how deep this twisted rabbit hole goes. Or who our sponsor is. I fix it. Though in fairness, you might have seen that one coming. Is the battery in your device not lasting as long as it used to? Looking for a new project? iFixit has you covered. Stay tuned to the end of this video to learn about their battery replacement kits. Let's get this out of the way. While we have dabbled in it before, DIY battery repair can be very sketchy, especially with lithium cells. And we would strongly recommend leaving this sort of work to a professional. But the difficulty of the work is only part of the problem. Let me show you what I mean. Most lithium-based packs have three basic components. A case to protect the sparky bits. The pack itself made up of individual cells. They are 18650s in this case. And a battery management system or BMS. The BMS is the brains of the whole operation, monitoring and controlling the charge and discharge rates of the connected cells. Now, good ones will contain a host of safety features, like overcharge protection, overcurrent protection, short-circuit protection, and the like. Meaning that they act as your main line of defense against catastrophic failure. But they aren't the only one. The second safety is built right into the cell itself in the form of a pressure relief vent that is right here on the positive terminal. It's designed to vent the waste gas that's generated by internal short circuits that naturally occur as the cell ages. This prevents the cell from pressurizing, creating an explosion hazard. You've probably experienced cell bulging or expansion before if you've got a really old laptop or phone. It's a similar idea, except that 18650s have a rigid outer housing, which won't just puff up. So with all that out of the way, this doesn't look so hard. Let's head to the shop. Since our original intention was to replace the cells inside many of our aging battery packs, not just make a video about it, we snapped up this beast of a 30 kilogram spot welder off of Craigslist for about $150. Seemed like a good investment. But it didn't have the correct leads on it for battery spot welding. So $70 worth of Amazon shopping later, and we've got a pretty solid spot welder at our disposal. We'll have a link down below to the leads that we used here. And compared to our DIY lead acid battery spot welder, so far, this is working a lot better. Before we begin, let's talk safety precautions. We've got our fire extinguisher, though that's unlikely to do much of anything with a lithium fire. So we've also got our fire safe workstation here with a fire brick that we'll be doing our actual welding on. Gloves and tongs in case we actually need to handle a ruptured cell. A sand bucket with additional sand to dump over top of it. Our fume hood, as well as a pre-propped door for us to take that sand bucket and rip it outside in the event that we need to get rid of it. Next up, let's talk about preparation for our pack. Because we have multiples of these red battery packs, we actually pre-disassembled one for you guys so that we can get going right away. But the process is simple. You just want to desolder the leads that run between the BMS and the battery pack itself, which includes the power leads, the balance charging leads, which are these guys right here, as well as this thermistor, which is going to monitor the temperature of our pack, assuming that we are able to actually reassemble it with the new BMS. One other critical safety measure is disposal of our old cells. We're going to go ahead and cover up all of the contacts with something non-conductive, like electrical tape, and put it into our sand. And you might be thinking to yourself, well gee Linus, that pack probably only has one or two bad cells in it. Why don't you just swap those out with good ones? No! We don't do that. We never ever do that. There's lots of electrical engineering reasons not to do it. Don't do it. All new cells. Of course, getting your hands on new cells is not always the simplest thing ever. And you need to make sure that you do your due diligence to ensure that you're getting genuine cells rather than counterfeit ones, which can have issues with reliability, capacity, and safety. We picked these up from a local vape shop that we have enough of a relationship with to trust. And what Colin's doing is he's checking them, not to make sure that they're genuine, but rather to make sure that they are all at a similar enough voltage that when we go and spot weld them together, they're not going to suddenly equalize. Yeah. And it's good we did that because I found five cells that are low. So these are 3.2 volts where everything else is 3.491. Depending on how long it's been sitting in inventory, it might have drained more or less. And we don't want that. Our next order of business is to arrange the cells in exactly the same orientation before we spot weld them together. And there are a number of ways to do this. You can get these little spacer kits off of Amazon. But unfortunately for us, if we compare to our assembled pack, these leave a space as advertised and the original pack does not. So we might have to improvise a little bit if we want to try to fit our battery into the old housing. One idea we had was to sacrifice one of our batteries and use it as a kind of holder. Here we go for our new cells. And then pop it out when we're done. Maybe cut it away while we spot weld it. I don't know. Another complication that we have to overcome is that we are using generic nickel strips. Whoop. There we are. Make sure you're using genuine nickel, by the way. While Red is using obviously some pre-cut ones that look a little bit different. What do you lean towards, Colin? Using this boy as a holder? I think we should snip it in half. Yeah, that way we can solder the top side. Flip it over and solder the bottom side while still having support on both sides. I really like it. Let's run it through the bandsaw. So these are all positive terminal up. Boopity boop boop boop. Oh, this is going to work. Okay. I think what we're going to do. We're going to put them on and then yeah, and then we'll wrap them. And then I think we're in really great shape. Colin was like, I don't think we're going to fit this back in the original housing. And I'm like, I want to try. My life's in your hands, Colin. Actually all of our lives are in your hands Linus. All right. That's not good. I'm kind of imagining that I hold this and you wrap the tape. There we go. I have seen dumber things. Now at this point, we could start laying down our nickel strips and spot welding everything together. But if we make even one mistake, we are A, evacuating this room and B, starting our project completely from scratch. So we want to go ahead and do some test welds. Now we got this all dialed in for a single layer of nickel strip over a test cell. By the way, shout out to the vape shop again for giving us a bunch of testers here. But what we haven't tried is two layers. So I'm going to play around with this a little bit and see if we can get a nice clean spot weld on some of our test cells here. First spot weld. There's a little bit of spring tension in this. See, we want that spring to go down. Then we're going to go ahead and it's definitely on there. Let's grab another one and let's try two layers. You should usually do two hits. Oh, I will. I will. I will. Don't worry. So we're doing a weld heat of 690, a ramp speed of three, and we think this means 14 milliseconds. Let's see how it handles two layers at our current setting. I think it will be fine. You know what? I don't think we have to change anything, Colin. Oh, no, it popped. Okay. Try again. Just clean up the tip. Okay. Now do that 32 more times. Okay, this is pretty sweet. I'm having fun. Now this is where things get a little bit interesting. We're about to do our second layer. Colin, you want to have a look at this and see how it's going? I need a clipboard so I can grade you. Yeah, thanks. It looks like a battery pack. This is the part I'm most nervous about because we need to do four cells in a row, and this is where we're first going to connect positive and negative terminals. So this is where we find out how Colin's measurements went. Hoping for no sparks. No sparks, Colin! Yay. You sound less enthusiastic than me. Were you hoping for some sparks? The thing about super high current is that it doesn't just melt your nickel and your cell together. It also melts your tips if they're not great tips. You know what, maybe we won't have the link to where to buy these down below. They're really not that great. Okay, great. I'd also like to take a moment to point out that I'm a total amateur at this. So if you're looking to actually build your own battery packs, there are lots of other better resources out there. Yep, same. That was a matter of time. Ah, fudge. Well, we popped one. Ah! Think I didn't clean the tip often enough. Well, that was a bummer, but the good news is the video's not over. We had a backup plan because we knew going into this that lithium batteries are much, much more volatile than the nickel metal hydride batteries that you might find in your parents' old power tools. Not only are the cases much thinner, which improves power density but makes them more susceptible to rupturing, but the lithium inside them is chemically much more reactive. You guys have probably seen the handful of videos on the news of electric vehicles bursting into flames. That's a lithium battery fire and it is no joke. Not only are they essentially un-extinguishable, but the smoke they emit is toxic too. We actually dumped more sand on that and moved it away from the door next to the concrete wall. There will be no fire there. So, here is what our backup plan is. Rather than trying to tackle a 16 cell pack, we're going to take one of our smaller Sony-style batteries, which has just four cells, and try to rebuild this one. The silver lining in all of this is that now you guys get to see the entire process, so there you go. We've pulled the housing off of the BMS here. I'm sure all of the DIY e-bike battery folks have already left their comments. Wow, they're using really pinner nickel strips on this. Look at this. The minimum possible amount of nickel was used. Backup sand bins right here. Yeah, we got it. Alright, thanks Colin. Anger level is so high right now. F***. F***. Well, we're down to four matching cells, so this will be our last attempt. Are you guys ready to go again? Yeah, I've got a good feeling about these batteries. What we need to check now is if my leads are going to line up with the BMS though. This guy is going to go here, and this guy is going to go here. So I'm just going to trim those down. Here we go. And then I'm going to double check again to make sure I snip off the right part. I'm okay. I'm okay, boys. You know what? Now's a good time to throw it into the housing then. Tell me something, David. Yep. Would you put this pack in a camera? Do I own the camera or is it your camera? It's my camera. Uh, maybe. And this is where we bunged it up last time. F***. Do you believe? I believe. Sandpaper between? Yeah, you better believe it. Two more strips. And then this one, this last one here, actually needs to be quite a bit longer. Do we got this, guys? Theoretically, that's it. Where's the multimeter? We should all see seven volts. Here we go, boys. Better have seven volts. Six point nine eight. We're short. Uh. Yeah. Kidding, kidding, kidding. I just want to cut away this little square here. Rats, I cut away more of it than I had meant to there. Let's solder a wire to it. F***. F*** me. We had a mishap with our first BMS and the snips. And unfortunately, when I saw the spark, I kind of jerked and moved fast. And I'm not sure whether the spark was from shorting the battery or shorting the BMS. So we might have killed the BMS, which means that we had to go find another sacrificial battery, which was also on its last legs anyway. And we're going to use that BMS. So I'm just going to go ahead and solder that guy. What do you think, guys? Much higher chance. Nothing. This time I'm surprised. It's as good as you can get. Yeah, there's nothing. We didn't do anything wrong this time. Check the pack voltage. Battery. Seven volts. All that means is that these pads are definitely connected. Please tell me this is a cheap light. It's a monitor. It's not cheap. Oh, it's a monitor. That's it. This time, I'm sure we did everything right. The pack is assembled correctly. The BMS went straight out of a working one onto ours. I'm really surprised this didn't work. Actually, point of clarification, I'm furious, but not surprised. Let's talk about that. We discovered in our initial research for this project that even if we had successfully welded together a battery for this red brick, it wouldn't have come back to life. And the reason for that is because battery manufacturers are f***ing us. There are multiple tiers of anti-right to repair behavior. One of the simplest is mechanical obstruction, where manufacturers use brittle plastic, glue, single use fasteners, and other similar strategies to make repairing their devices impractical. Sometimes this is just plain not caring about the user or the environment, while other times this happens for malicious reasons like planned obsolescence. Either way, I promise neither of them will ever happen with our merch from lttstore.com. Get yours today. The next tier of anti-right to repair behavior is soft obstruction. This is almost always on purpose and exists solely to prevent end users and third parties from repairing or rejuvenating their devices with manufacturers often citing safety as a justification. That is what we ran into with, well, would have run into with our red pack and appears to be what we ran into with our other pack. But how are they doing that? Well, there are four different types of BMS, dumb, basic, smart, and evil. Dumb is no BMS at all, like these RC lipo batteries. Each cell's voltage is maintained at the time of recharging by a much more sophisticated battery charger using the balance lead. A basic BMS allows you to safely use and charge the battery pack with a simple charger while protecting against under and overcurrent situations. So a lot better than nothing. A smart BMS will include cell balancing and some level of capacity learning along with self resetting for faults and ideally the ability to resell. No, not like this on Facebook Marketplace to replace the cells like we attempted today. Finally, there's evil BMSs, which thankfully we don't see that much of these days. What makes them evil is that after a set number of charge cycles, they will switch off permanently even if they could still work. And if you as a manufacturer ever built this sort of intentional e-waste, shame on you. All of which raises some questions then. What exactly did we see today? According to Tyler from THTBattery.com, red batteries, at least these older red bricks, are extremely challenging to resell because there's a good chance the BMS will simply not wake up after the operation. He hasn't put the R&D into solving the problem because there just haven't been enough requests. But there are a couple possible explanations for this. The malicious one is that Red's contract manufacturer could be using software to detect either cell disconnection or a change in capacity that will shut down the BMS on purpose. In which case, it's basically an evil one for all intents and purposes. The good news is that replacing the BMS with a generic one for about $17 could get you back up and running if you don't need the original indicator lights or anything like that. The careless possibility is that they used volatile storage for the BMS's programming that wipes itself if it loses power. Given the cost difference, this honestly could also be considered a malicious design decision. Now, something that I want to make clear at this stage is that I am not advocating for user serviceable battery packs. Considering the precision required for safe assembly and the volatility of the chemistry, that's just not realistic as we observe today. But there's a middle ground here. Ah, yes. This pack is made by a company called Bebob, a German battery manufacturer that just so happens to supply one of the largest cinema camera makers in the world, ARRI. They advertise their cells to be replaceable and they even have an indicator that tells you when you've reached 80 and 60% of the original capacity. When that happens, you can send it to them and they will replace the cells at a discount. Other cinema brands, take notes. We're not even asking you to be as awesome as Bebob, but the least you can do is not put up roadblocks on purpose. So then the safest way that you can help right now is just returning your batteries to be recycled when you're done with them. But in an increasingly electrified world, producers of battery powered devices have a responsibility to plan ahead and to extend the lifespan of their products and figure out what's supposed to happen to them when they reach the end of their life. On that note, as it turns out, one of the largest battery recycling facilities in North America, Retrieve Technologies, is just a few hours away from us. So let us know in the comments if you want us to go check out how it's done in person and get subscribed so you don't miss it. And don't miss our sponsor, iFixit. iFixit wants to help you keep your new devices powered up like when they were new. iFixit has a wide range of battery replacement kits for your mobile devices, kits for laptops, cell phones, tablets, smartwatches, and even Nintendo switches. You don't need to be an expert to repair your devices because each kit comes with simple to follow step by step instructions with photos to walk you through your replacement. So learn a new hobby while saving yourself some time and money by going to iFixit.com slash LTT. If you guys enjoyed this video, maybe you'll enjoy our other This Should Be Illegal video where manufacturers were caught swapping components on SSDs, effectively advertising one thing and delivering another.