If you want to practice, I have a load of cells you can have. they're from faulty e-bike batteries, but most of the cells are OK.
Wow, sounds an offer I shouldn't refuse.
Assuming 'most' of the cells are OK, then there is the possibility of a working battery at the end of the project?
When I took my old battery apart and pulled out 40 cells, 3 were completely duff while about a dozen showed a slightly lower voltage while the rest were up to power.
What did take me though, there wasn't a single indication, whose batteries they were though I was lead to believe from the original vendor, the battery cells were Panasonic.
The big stumbler though, being OEM I assume, no signage of what capacity they are. It would be lovely to have a bucketful of used cells and grab some, all reading the same full voltage but without knowing their capacity it would be dangerous I would have thought to try make a working battery? Have you some way of knowing their capacity.
If to indulge and make a battery I would like to try make one similar in capacity to the one I bought to replace the old one as already I have discovered, due to the terrain in these parts, the extra capacity is really a must or I will make the mistake again, of draining the battery on a run which you all say, is a no,no, if we want to make our batteries last longer. Ideally I would be looking at say, a 10s 5p project with 3000ma cells, looking at a 36V 15 AH rig at the end of the job. 50 cells.
Joseph