BMV 712 calculating SoC incorrectly

Q&A and troubleshooting
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1

I have BMV-712 smart monitoring a 3750Ah battery. This capacity value has been set in the BMV.

Ive carried out a 48hr discharge test with all charging sources disabled. The 48hr consumption is 1493Ah as recorded in the BMV.

The SoC was at 100% at the beginning of the test, and 73.8 % at the end, so 26.2% decrease, a quick bit of maths equates this to the a total capacity of just over 5100Ah, which is over what is programmed?

Does the BMV take into account the discharge rate and increase capacity accordingly? Or is this just a calculation error within the BMV?

Thanks in advance for any help on this one.

2

The BMV uses the Peukert exponent to cater for the varying capacity of lead acid batteries at different discharge rates, the manual covers it, just not sure where. Search this site or the manual for “Peukert”. You will find many answers yo this repeatedly asked question.