Stops charging at 80% Sigineer inverter charger plus overkill bms

[bobbie_ohio]

Just finished a sump pump backup with 8x100ah EVE cells, a Sigineer 1500w charger/inverter and a 100amp overkill bms. Any of these bms settings look like they would stop me charging at 27.3v and not go to at least the 8x3.55v I have set as cell full voltage ? Or is the 80% just a calibration issue?




There’s almost no settings on the inverter except battery chemistry (set to lifepo4)

Thanks

 

[sunshine_eggo]

Have you read the manual for the LFP settings?

How much voltage drop between the inverter and battery terminals while charging?

Set balancing to 3400 and 20mV.

If you've never charged this battery to full before, the BMS SoC will not be accurate.

 

[Browneye]

If your cells are only getting to 3.4Vpc then it's going to show as 80% SOC. Either that or the blank fields are causing the bms to display the next lowest entry - in this case it would be the 3.4Vpc and 80%.

I would start out with the recommended values from Overkill - and I'm pretty sure cell full voltage is 3.65Vpc.

EDIT: Just looking at the OK manual - cell 100% charge voltage is 3.5Vpc.

 

[bobbie_ohio]

Have you read the manual for the LFP settings?

How much voltage drop between the inverter and battery terminals while charging?

Set balancing to 3400 and 20mV.

If you've never charged this battery to full before, the BMS SoC will not be accurate.

I initially top balanced them all with a cc/cv 10amp charger

 

[sunshine_eggo]

I initially top balanced them all with a cc/cv 10amp charger

Awesome. Top balancing cells is not fully charging a battery. The battery is the cells and BMS working together.

Are your cells actually balanced? It's pretty common for folks to wait too long between top balancing and deployment and discover they lose their top balance.

 

[bobbie_ohio]

Awesome. Top balancing cells is not fully charging a battery. The battery is the cells and BMS working together.

Are your cells actually balanced? It's pretty common for folks to wait too long between top balancing and deployment and discover they lose their top balance.

Was doing one battery a day for 9 days then deployed so earliest battery was 10/11 days out.

 

[sunshine_eggo]

Was doing one battery a day for 9 days then deployed so earliest battery was 10/11 days out.

Just to clarify, a cell is a singular unit of charge. A battery is a collection of cells.

10-11 days is more than enough time to develop another imbalance. Are you showing any cell issues while charging?

 

[bobbie_ohio]

Not that I noticed. I’m running the thing down to cut off values now. Been pulling just under 1500w for over an hour how. I’ll recharge from there and see what happens