I have a number of 18650 cells which I would like to be able to keep at 3.8V for long-term storage.
I have a Tenergy unit which I have used for this with one cell at a time. It is capable of draining at 1A.
I have a bunch of cells now and I need a more convenient way to discharge them than this method. Maybe a 4 or 8-bay unit. I’d charge to 100% and then stick the cells in the parallel and do a 1S discharge (right? Or should I make a balance discharger so I could start with cells at multiple voltages? My Tenergy could support that).
Most of the 18650 holders I see on Amazon have little pins sticking out of the bottom of them—they look like they are meant to go into holes and be soldered on to something, but I’m not sure what. I have a soldering iron. Maybe I could use magnetic contacts so I could drain various sizes? I have some neodymium magnets, but they seem to be really poor conductors.
Things I’m looking for in a list:
- 4 to 8 cells simultaneously
- handle protected (long cells) and unprotected
- fairly durable
- leads are thick enough to handle current without getting hot
- easy to get the cells in and out (the cells won’t live in here—I need to get them out so I can put the next batch in)
I think I’ll have to make this thing, but I want some parts as a starting point.