coulombs counting BMS

[Roswell Bob]

Do most BMS count Coulombs to determine SOC? I am thinking to rum my packs from about 20% to 80% SOC and expect Coulomb counting may be the best way to control charging.

 

[Supervstech]

I am not aware of any that count... all I’m aware of simply have voltage parameters per cell...

 

[Roswell Bob]

Ok. Then that's most likely good enough. I suppose if there was an advantage then it would be used.

 

[Supervstech]

There is certainly an advantage to counting. For measuring capacity and measuring degradation of the bank...
But the BMS doesn’t do that.
For that you need separate monitors.

 

[Bob B]

Maybe ask about a specific BMS .... ones like the basic Daly don't provide any info.

Ones like the JBD sold by Overkill Solar and the Chargery BMS do coulomb counting.

 

[Ceberha]

My Overkill would count Ah up during charging, but the Ah did not come down under load. I just hooked it up last week, and have been meaning to ask if I need to change some setting to enable this.

 

[Bob B]

My Overkill would count Ah up during charging, but the Ah did not come down under load. I just hooked it up last week, and have been meaning to ask if I need to change some setting to enable this.

I would recommend starting a new thread instead of side tracking this one.

 

[Roswell Bob]

I recall using a lithium chemistry that had a flat discharge curve so that it was necessary to count the amp*hours. The LIFePO4 cells have a steeper curve so that a voltmeter should be good enough. Thanks.