Part 1 : Salvaging old packs

Hey guys! I got another project that I started a little while ago. I want to make a power station from repurposed 18650 batteries from old laptop packs. Initially, it started with the idea of testing my old 18650s, to fill up some USB battery packs but I soon decided that I wanted something much bigger in case we need power where no power is available. ( it came to the realization after we had big floods in the region and, lots of houses got their basement teared down because they didn’t had power and a sump pump… and we would like to have some kind of security in case ). Enough with the background and here’s some ‘progress’.

As I was saying, It started with me getting a tester, that I wanted to test my current 18650 batteries. It is an Atorch DL24, which initially was not supposed to be supported on Linux, which was kinda sad since my bench runs on a rPi using Linux for the OS. I wanted to have charts and all that kind of fun stuff but running a Windows box was out of the question. I was ecstatic when I realized that some amazing people on GitHub reverse-engineered the communication protocol and developed a python system to interface with it ( you can find it on GitHub under the name KrystianD/dl24-electronic-load )!

I even made a spreadsheet to keep track of my good and less good cells! Yes. I’m a nerd. I admit it. >.>

Nonetheless, I knew I’d need WAY more battery packs than what I had on hand so, I decided to look online on FB marketplace and stumbled on this weird post. The person had a ‘box of laptop batteries’ with other accessories for dirt cheap. My initial check online made me realized that laptop packs are worth 2-3$CAD each, so I analyzed the crappy picture supplied on the post, and thought there was more than 12-15 packs so, it was a good deal. We indeed got the deal and my partner asked me to bring a plastic bin when they got home. We counted and there was…. 68 battery packs! so, each packs were a mere 0.45$CAD. QUITE a deal if you ask me!

After a bit of time (roughly 2-4h for each cell to test), I had a bit done, and some left… (as of this writing, I’m on cell #0067 but the picture was taken roughly on cell #0040, out of ~900-1000, the rate of testing will definitely increase in the future. Fear not, got something planned for that). I split my bins in 3: To charge, To test and Tested. I only keep the batteries that are over 50% of their original mAh rating. Here’s a shot of what I had tested vs to test. It is a VERY lengthy process to say the least.

Although, I had some bad experiences with some packs. Most of them were opening up fine with no problem, or barely any force (a good spudger will do magic!). Some were a bit more.. painful (I may have badly cut myself once of twice) and some were totally terrible. Actually, one was in such a bad shape that the cells ripped when we opened it, with all the bad stuff that could happen: terrible smell, risk of shock and so on. I quickly got these bad ones in individual bags until we bring them to the recycling center for proper disposal. My guess is that that pack exploded or something like that but I’d definitely have to do some more research to understand what happened there. Still scary when the casing rips apart and the black goo is exposed.

So that’s pretty much it for that right now. Although the Atorch DL24 is on my list of stuff to review. spoiler alert: I’m very very satisfied with it yet. 😉

To be continued…