Dewalt 24V Recip Saw + Roomba Batteries

1st post dont laugh at the noob I dont understand why this confuses me as much as it does
K so I bought a used Roomba Vacuum with a dead battery, got suckered into buyingone of those 40million mah fake liIon batteries that lasted about 3 weeks total... So tore it apart and have 8 replacement cells I would like to use plus the BMS out of the "fake" battery that hasbeen sitting on my shelf for the better part of 2 years
I also have a dead NiCad 24v Dewalt reciprocating saw battery that I would like to rebuild using LiIon cells but unsure of the best way to go about designing the 16 cellbattery with the suggested voltage (24v) andthe highest mah.Both batteries will have 18650 cells
Any help would be appreciated !
Roomba BMS

WickedJack said:

1st post dont laugh at the noob I dont understand why this confuses me as much as it does
K so I bought a used Roomba Vacuum with a dead battery, got suckered into buyingone of those 40million mah fake liIon batteries that lasted about 3 weeks total... So tore it apart and have 8 replacement cells I would like to use plus the BMS out of the "fake" battery that hasbeen sitting on my shelf for the better part of 2 years
I also have a dead NiCad 24v Dewalt reciprocating saw battery that I would like to rebuild using LiIon cells but unsure of the best way to go about designing the 16 cellbattery with the suggested voltage (24v) andthe highest mah.Both batteries will have 18650 cells
Any help would be appreciated !
Roomba BMS

Click to expand...

Just a few thoughts to get you on track.


If you want to use the fake battery BMS you should test it a bit. Consuption, if it has some, switching limits per cell. Or better simply buy a cheap one out of the chinese stock.
I have 1s,2s,3s,4s and 6s bought and they worked fairly well within their promised data.

You should know that "BMS" can be the over/undervoltage protection, with or without any balancing feature. You should not go without any balancing, but can do it with the charger, like the knowm B6AC (by a genuine).
Tell the voltage of the roomba ?

24 Volt as LIon is either 6s or 7s, same procedure. You need BMS and balancing.