Rebuild a laptop battery pack

Hello! So in today’s episode, I’m going to be showing you how to rebuild an old laptop battery. Now in this particular example, I’m going to be using this old ibook clamshell, but keep in mind that what I’m going to be showing you really could be applied to just about any laptop or even an appliance like a cordless drill. Okay, now one of the first things I wanted to tell you is there’s really no reason to be apprehensive about doing a procedure like this. Take this battery for example, I mean it is dead. I mean it is totally dead. It will not run the laptop even for 10 seconds, so no matter what I do to this battery I’m not going to make it any worse off than it is now. Okay, the first step is to take the battery apart. This particular one is held together by snaps. Some batteries use screws and some even use glue, but I’ve never come across a battery that couldn’t be disassembled with some patience. Okay, so once the battery was apart, I knew what kind of cells it used. As I suspected, they were 18 650 cells, or around 3.7. Volts. So the next step was to jump on eBay and buy some. Alright, so let me give you a little warning about buying a lithium batteries on eBay. if You buy a cheap, Chinese battery like an ultra fire, you can be absolutely sure that whatever they list as the milliamp hour rating is a total lie. For example a good battery like made by Panasonic or Samsung will typically advertise a milliamp hour rating of somewhere between 2000 and 2500, and that’s pretty realistic. Now if you look at for example these ultra fire batteries on eBay, you’ll see they’re advertising 6,500 Milliamp hours. That is total bull. So realistically, the sad part is is these batteries actually have even less than the name-brand batteries. When people have tested them they’ve actually found they’re more like 1000 or 1500 milliamp hours rather than 6500. I mean think about it. The Tesla Model S uses 18 650 batteries. If 6500 milliamp hour cells really existed then that car would be able to get around 730 miles of range, instead of 280 miles. But what they are is super cheap. Yeah, I actually paid like $1 apiece for these batteries, and that’s actually pretty good because a name-brand battery would run more like four or five dollars apiece, and since this is not a computer, I really need a lot of runtime on, it’s mostly just an experiment, you know I’m okay with the lower milliamp hour rating. One thing that’s good to do is sort of sketch out the arrangement of the cells. How this battery pack is set up is that the cells are actually paired together, and the pairs are arranged in series like this. The main Power Connects at each end, but there are sensor wires between each cell pair for monitoring and balancing. In fact, if I really wanted to be cheap, I could actually eliminate four cells of this pack and it would still work just fine, but the run time would be cut in half. By the way, when working with batteries, I always like to keep one of these nearby, just in case I overheat one in order to go into like thermal runaway or something. So, now that I have the cells out of the battery, I need to desolder them, and one of the things I found out was that these metal clips were actually welded on, so I was not able to desolder them, so I had to use wires as a substitute. One of the first things I did was put some initial solder on the battery terminals. You need a pretty strong soldering iron to do this, as you have to heat the battery up pretty quickly to do this. You have to make sure the solder action has actually stuck to the battery like this. Of course, you have to get both sides, and the negative side is a little harder because there’s more to heat up. So then, I stripped some of the wire and began the process of soldering it onto the battery pack. I found it easier to take the batteries in pairs while doing the soldering, and I also eventually set up some wood blocks into kind of a jig that helped hold these together while I worked. Once all the main connections were done you could see how it mimics the design of the original battery pack. All that was left to do now is connect the original electronics to the cells. Then, I put it all back inside the original battery pack, and of course snapped it closed. Well, the cells apparently had no charge whatsoever, as the computer would not turn on, so I had to plug in the AC adapter. After a moment, it started to take the charge, and before long I could actually see the percentage start to rise. But keep in mind the battery pack is not calibrated. the only way to actually calibrate it would be to go ahead and fully discharge the battery and recharge it several times. That way the little microcontroller inside the battery pack would be able to learn the actual capacity of the battery. Once it was charged up, I unplugged it instead of timer going so I could see how long it would run. I turned off sleep mode to make sure that the computer stayed at maximum drain the whole time. So I’m not even sure how long a brand new battery is supposed to last on and iBook Clamshell. Now in the past, I’ve had used batteries go as long as two and a half hours, so my guess is a brand new one would do three, possibly even four hours. So it’ll be really interesting to see what these cheap batteries will do. So I noticed around the one-hour mark it was still going strong. So far so good. Or so I thought. It turns out it went into suspend mode not too long after and wouldn’t wake up. So I had to plug the power cable in, and sure enough it was drained to zero. So it turns out these el cheapo batteries from eBay will only run the computer for about 1 hour and 35 minutes, which is probably at least half of the original run time of brand new batteries, so that means the milliamp hour rating on these batteries is, like I mentioned before, probably closer to 1,000 maybe 1500 at the at the absolute best. So overall I’d say it’s a successful product because I pretty much knew what to expect when I was getting into it and so that’s just kind of a warning on those eBay batteries. You know, you get what you pay for, so as long as you’re okay with with the cheaper batteries and you know what you’re getting you know that’s fine.