Hi, I'm driving a 12V load for ~1s second very infrequently, at a draw of about 30A. The load isn't particularly voltage-sensitive. Total mAh isn't that important.
I have a supply of recycled laptop 18650 cells so was looking for a solution using those (I am aware they will be unreliable). I will charge them individually outside of my circuit, so charge balancing is not a requirement. However I don't think they have over-drain protection built-in, so that needs to be considered. Their positive terminals are flat.
After some searching I think I need a 4 cell holder, wired in series ("4S"), stepped-down to 12V somehow.
Searching eBay reveals hits for "4S 30A 12V balance board". Is this the sort of thing I am after?
- Continuous discharge current: 30A (MAX)
- Instantaneous discharge current: 70A
- Power balance detection voltage: 3.60±0.025V
- Overcurrent detection voltage: 150mV
I looked into using 3 cells with buck-boost converter, but it seems more expensive.