A couple of weeks ago, I got a huge pile of used laptop batteries. I disassembled them and re-used the cells in my DIY project, here’s the project log.
Get some 18650 li-ion batteries
So I went to this flea market in Uppsala (Sweden), and I scored about 20 old laptop batteries for roughly 10€.
As soon as I got home I started disassembling them to get all the good stuff: the 18650 li-ion cells. Here in Sweden it cost more than 10€ to get only one of these. And I’ve been reading a lot about fake ones coming from china. Here with Dell, Asus and HP battery pack I was sure to get great quality cells.
Opening all these battery packs took a whole evening, but the process is pretty straightforward, you pry open the pack, and separate the battery packs. As long as you keep in mind not to crush or short circuit the batteries you’re good to go.
As I separated the batteries I tested them to see which ones are salvageable. Idea goes like this:
- Between 4.2v and 3V the battery is in great shape
- Between 3v and 2v the battery is under the limit, but can still be recharged without much loss.
- Less than 2v the battery is ready to be recycled (it might be recharged and work for a while but it’s probably not worth it)
Here’s the final count, I got 114 batteries alltogether:
- 66 good
- 26 “tired”
- 22 dead
That’s 96 good 18650 batteries, from a nice brand. Not bad eh? 🙂
Charge them up
Once I got all these batteries, I had to find a safe way to charge them, so I got a nice charger, the Nitecore D4. It costs about 25$ and is able to charge 4 batteries at the same time.
Then began the loooooooong road to charge all these batteries, at approx. 5h per battery, this is taking forever.
Now that you have a bunch of charged 18650 li-ion batteries, you need to make sure your projects never draw the batteries below 3V.