Is it possible to add protection circuitry to unprotected 18650 batteries? If so, where would a person buy the parts to do this?
It looks like DX.com has some SKU: 26114 is for 14mm dia cells they may have others.
Two different ones here. It appears they are either 2 or 4 amp.
Thanks. I know this is a stupid question, but how do you attach these to the batteries? Do you have to solder to the negative end?
Personally I would avoid any protection pcb which doesn’t use a seiko chip. Seiko is regarded as the best, all of the better batteries seem to use them. Protection chips sometimes fail, I suspect the failure rate is higher with those other random chips.
2pc 18650 4A-6A Seiko protection $5.98 ($2.75 / piece) free shipping.
20pcs 18650 4A-6A Seiko protection $25.66 ($1.10 / piece) free shippping
Wire strips
Kapton tape is used to isolate the wire.
Anatomy of a Protected LiIon Battery
They're welded, but you may have to solder. A battery tab welder costs about $150. There's a guy on the other forum that plans to do a write up when he gets his.
Just adding more stuff to go wrong. Use quality unprotected cells, charge them properly, check them often. You should be doing those things anyway.