Ryobi battery not charging

[ffrree]

I know this is not for this forum, but it is 18650 batteries related, hope someone can help.

I have a Ryobi battery which has 5 x 18650 cells of 3.6V each. It just won't charge at all. The battery has only been used infrequently for about 4 months.

The voltage of each cell is 3.3 volt, so they should be healthy, and the total voltage at the battery terminal is 16.5 Volt which tallies with that.

The battery charger is trying to pump charges into it at 20+Volt, measured at the terminal, which looks o.k. to me, but it just would not charge.

Don't know if anyone here knows the circuit Ryobi battery's bms to point me to some direction for more investigation.

BTW, it is just a curiosity of mine to look further, otherwise I'd just go get a new one.

 

[Diysolar123]

There are a few things that it could be which are not obvious...

1) many battery commercial packs are really focused on safety; so they have internal circutry that "permanently" will shutdown what they think is a bad battery. If they sense an odd cell voltage, over voltages, etc., well, they basically suicide the battery pack and its dead.

2) well, it could just be that the charge controller board did just break, things do break.

3) most tool battery packs are li-ion and NOT like lifepo4; so they will damage themselves rather quickly at just 3V/cell.

sounds like the cells may be in good condition, remove the cells and test them out, at least you have some nice 18650 cells, maybe.