Eg4 battery cell with low voltage.

[JoshVannette]

Good day, I have a eg4 48v 100ah battery that has a single cell that is reading 2.9v when all others at full charge. Should I replace the cell, pull and top balance? It's out of warranty with Signature Solar.

Recommendations on what to try or test. Checked balance leads and everything looks tight.

 

[sunshine_eggo]

Good day, I have a eg4 48v 100ah battery that has a single cell that is reading 2.9v when all others at full charge.

what are the other cell voltages?

Should I replace the cell, pull and top balance? It's out of warranty with Signature Solar.

Recommendations on what to try or test. Checked balance leads and everything looks tight.

Verified cell readings with a separate voltmeter?

Can you individually charge the single cell?

If so, will it hold voltage?

 

[JoshVannette]

what are the other cell voltages?



Verified cell readings with a separate voltmeter?

Can you individually charge the single cell?

If so, will it hold voltage?

Verified with voltmeter
I'll need to buy a charger to top balance and pull that cell
The original BMS on this unit was not working so i installed a Daly 100amp smart bms as a replacement. Battery was in storage for 6 months. Attached a pic of the Bluetooth reading from the Daly smart BMS app. Want to replace all my BMS with overkill or JK I think

 

[sunshine_eggo]

okay, that certainly changes the picture. I would not assume the cell is bad if there was a prior BMS problem. Those cells look pretty messy.