Kobalt 40v battery packs BMS

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New member
Nov 14, 2020
Ok I found myself getting a few hundred of these 40v batteries and have been removing the batteries to reuse, I'm wondering if the BMS is worth saving. Some are the 2Ah packs some are the 4Ah packs and a few are the 5Ah packs. Are the BMS worth saving?
What kind, brand of packs? Stating they are 40V with 2Ah doesn't help much ;)

Depending on the battery, if the bms is still functional (some times that's the reason the battery pack is "dead", for instance) you may be able to reuse them. However, the bms is generally only good for about the rated amps for that one pack, not repurposed into a larger pack that would see much higher amps.
Breaking down the packs they seem to have 1 or 2 bad cells, the 2Ah have 10 cells the 4Ah packs have 20 cells and the 5Ah have 20 cells as well.
lol was thinking the SAME thing.
Every pack i take apart has a BMS and i always thought about saving some of them incase i wanted to build a pack with the same setup as the original…
from my understanding, if you had a small pack and thought; "hey, i could use a 3s3p or a 2s3p 12v battery pack", you could use the circuitry from that pack and replace all of the cells and reconfigure it. or replace the dead cells.

maybe you can use some of them to make a charger...
Depends. Do you have any Kobalt chargers or equipment? When I was making my ebike battery, I already had a bunch of Ryobi 40V BMS's, chargers, and connectors, so I just picked one out and ran with it. Worked with my 36V ebike and it could handle the 750 Watt motor without a problem. And I didn't have to buy some Chinese BMS. 20210527_230122.jpg
I have all the kobat 40v tools, 4 mowers, hand saw, pole saw, hedge trimmer, leaf blower, edge trimmer and 12 chargers I only use 4 chargers and the newest 5Ah batteries for my tools so I have alot of leftover stuff.
3 of the mowers are the older double blade double batty ones, my news mower is single blade singe battery self prepepled
Sounds like a fun project. What I really want to know is how you managed to get a couple hundred batteries from a box store? I been slowly trying to build relationships with all the computer repair and hardware local shops but nothing big like that. I always save BMS boards for stealing parts from or repurposing for future projects. If I ever get too many piled up I will recycle them for money :) I don't know what your plans are for the packs but you could probably restore many of the packs and resell them. Probably worth more like that than individual cells.
3 of the mowers are the older double blade double batty ones, my news mower is single blade singe battery self prepepled
Would you be interested in selling some of your Kobalt batteries?