SOK's BMS balancing <14.4V

[SteveSS]

I recently purchased my first LiFePO4 batteries, two SOK 12V 206Ah, and I downloaded the spec sheet from the SOK Facebook Group. The balancing spec (<14.4V) seems odd based on what I've read elsewhere. I posted a question on the FB group asking for clarification. A SOK rep responded with this: "When the battery charging /discharging, the bms will balance the cells. But when fully charged or discharged, it would not balance the cells. When voltage on cells up to 14.4V ,bms will stop balancing and cut off." That sounds to me like continuous balancing up to 14.4V. Does that type of balancing exist?

 

[time2roll]

Yes that can exist depending on the BMS settings. The cells do need to have a certain differential before balancing will activate. The voltage of the cells will generally converge or become closer together in the middle capacity area so there might be little to no actual balancing getting done. At the top of the capacity the cell voltages will diverge if not well balanced and the BMS then activates the balancing.

 

[SteveSS]

Yes that can exist depending on the BMS settings. The cells do need to have a certain differential before balancing will activate. The voltage of the cells will generally converge or become closer together in the middle capacity area so there might be little to no actual balancing getting done. At the top of the capacity the cell voltages will diverge if not well balanced and the BMS then activates the balancing.

Thanks. I'm glad I don't have to occasionally fully charge them for cell balancing. Is it fair to say LiFePO4 would be happiest to never be fully charged?

 

[ChrisH]

What kind of charger do you use with your SOKs?

 

[SteveSS]

What kind of charger do you use with your SOKs?

I have 3. A Bogart SC-2030 (PWM) solar charger, a GoPower IC-2000 inverter-charger, and a Renogy DCC1212 60A DC2DC.

 

[SteveSS]

BUMP - Just wondering if anyone has tested/verified SOK's claim of (continuous?) cell balancing up to 14.4V. It's still nagging me since many other brands only begin cell balancing at 14.4V. I prefer not to charge mine that high.

 

[time2roll]

BUMP - Just wondering if anyone has tested/verified SOK's claim of (continuous?) cell balancing up to 14.4V. It's still nagging me since many other brands only begin cell balancing at 14.4V. I prefer not to charge mine that high.

Dealer Currentconnected lists the balancing starts at 14.4 volts. I agree this seems a bit higher than needed on a daily basis.

https://www.currentconnected.com/product/sok/

Consider charging lower on a daily basis and if possible set your equalization to 14.5 volts for maybe an hour every 10 to 60 days.