Hello, I have a pool robot that runs on batteries and stopped working. I took it apart and found the battery pack. The label states 10.8v and it has 6 cells so I assume 3S2P. I also checked how the batteries are connected and it fits the 3S2P layout. The readings are a bit off though: * When I check each pair of cells individually I get 4.1v. * When I check over the 3 x pairs I get 12.3v. * But when I check via the BMS chart/discharge port, then I only get 4.1v. This leads me to believe the BMS is faulty. Does that make sense? Thanks!

3S2P could it be the BMS is faulty?

slepax

Hello,

I have a pool robot that runs on batteries and stopped working. I took it apart and found the battery pack.

The label states 10.8v and it has 6 cells so I assume 3S2P. I also checked how the batteries are connected and it fits the 3S2P layout.

The readings are a bit off though:

When I check each pair of cells individually I get 4.1v.
When I check over the 3 x pairs I get 12.3v.
But when I check via the BMS chart/discharge port, then I only get 4.1v.

This leads me to believe the BMS is faulty. Does that make sense?

Thanks!

VatrerPower

Based on your description, the battery pack’s voltage measurements appear normal, but the lower voltage at the BMS output suggests that the BMS might be faulty or in protection mode. This typically happens if the BMS detects an abnormal condition, such as overvoltage, undervoltage, or a short circuit, and shuts off the output to protect the battery. If you’re not familiar with electrical repairs, it’s advisable to consult a professional to ensure safety and proper handling of the battery pack.

NoahMM

on amazon there are many 3s 2p bms boards for reasonable prices. based on the description you gave id say the bms is faulty. the cells seem ok though.