Replacement BMS for Powerurus battery

[FreeRangeMira]

I’ve purchased a Powerurus 12v 100ah battery based in Will’s recommendation. The first battery was defective and Powerurus (RowPow) support was great. They had me try a few things but determined the battery needed to be replaced and quickly sent me a new battery. The original battery had a huge cell imbalance between 2 of the cells according to the bt app. So with nothing to loose I opened up the battery. I measure the voltage at the balance leads and they are all within a few millivolts. Based on this, I assume the BMS is defective. I hate to throw away 4 perfectly good cells. Any recommendations for a BMS to replace the original in the battery? Anything I need to be aware of when replacing the existing BMS? I assume I want a 4s 100a BMS (that is what the original is). Any advice would be greatly appreciated.

 

[Darce]

I’ve purchased a Powerurus 12v 100ah battery based in Will’s recommendation. The first battery was defective and Powerurus (RowPow) support was great. They had me try a few things but determined the battery needed to be replaced and quickly sent me a new battery. The original battery had a huge cell imbalance between 2 of the cells according to the bt app. So with nothing to loose I opened up the battery. I measure the voltage at the balance leads and they are all within a few millivolts. Based on this, I assume the BMS is defective. I hate to throw away 4 perfectly good cells. Any recommendations for a BMS to replace the original in the battery? Anything I need to be aware of when replacing the existing BMS? I assume I want a 4s 100a BMS (that is what the original is). Any advice would be greatly appreciated.

How are the bms leads attached to the cells? Could it be a janky connection? I've had what I thought were good crimps and yet when I tugged the wire to the side the bms would present a bad cell. Re-crimped a new ring on fixed it. Just a thought.

 

[FreeRangeMira]

If I measure the voltage at the connector that plugs into the BMS the voltages are good. The BMS software / app shows different voltages. I think leads are fine but the BMS ADC circuitry is defective. I may reach out to PowerUrus to see if I can buy a BMS, but I’m not holding my breath.

 

[yodamota]

If I measure the voltage at the connector that plugs into the BMS the voltages are good. The BMS software / app shows different voltages. I think leads are fine but the BMS ADC circuitry is defective. I may reach out to PowerUrus to see if I can buy a BMS, but I’m not holding my breath.

BMS

If you want to know how to build your own battery, check out this page: Click Here If you need raw LiFePO4 Cells: Click Here

www.mobile-solarpower.com

 

[FreeRangeMira]

Yodamota, thanks for the link, I should have known to look there first.

 

[Darce]

Daly 12v 4s 100a
I prefer Overkill myself. Just one I found on ebay

 

[Tomthumb62]

I’ve purchased a Powerurus 12v 100ah battery based in Will’s recommendation. The first battery was defective and Powerurus (RowPow) support was great. They had me try a few things but determined the battery needed to be replaced and quickly sent me a new battery. The original battery had a huge cell imbalance between 2 of the cells according to the bt app. So with nothing to loose I opened up the battery. I measure the voltage at the balance leads and they are all within a few millivolts. Based on this, I assume the BMS is defective. I hate to throw away 4 perfectly good cells. Any recommendations for a BMS to replace the original in the battery? Anything I need to be aware of when replacing the existing BMS? I assume I want a 4s 100a BMS (that is what the original is). Any advice would be greatly appreciated.

Was opening up the battery all that difficult? Could you pry it open or did it require cutting?

 

[FreeRangeMira]

I was able to get a stiff putty knife under the top cover and pry off the lip that went around the battery. Semi destructive, but the top goes back on and I could tape it closed again. I didn’t have to cut the case yet. I may need to in order to replace the BMS. The Overkill looks like it would fit in nicely and I could use the existing wiring.