I got some Samsung 35E cells. 3,5Ah with 10A current.
I made an battery of 10S3P.
I installed cardboard covers for the positive terminals to protect. And i spot welded the batteries:
Here i’m going to fold those into what’s in next picture. (Quit making assumptions that this is folded from middle! It is two-way fold, like a book)
Installed the wires and connectors.
Made an enclosure with some paddings and made sure that wires are loose and that nickel stripes won’t cut the wires.
Then i wrapped it on duct tape so it’s sealed.
I have charged it every now and then with 42V and 2A. It started sparkling like an rocket and i tossed it outside.
Here’s what i managed to salvage
What do you think could have caused it? All the cells were oriented the right way, and connections were triple checked.
This was the very first time those cells were under a charge. series charging without balancing on 2A current. So it’s 0,2C rate.