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bill-strange avatar image
bill-strange asked

Victron Monitor vs. Built in battery life monitor discrepancy

I have (3) 100 amp Lion energy LiFePO4 batteries on a 12 volt system. Each battery has an on board battery life monitor. There is a wide discrepancy between the read out on the battery itself and the Victron monitor. Today, the batteries all were reading in the 40% capacity range while the Victron monitor was at 64%.

I'm not sure which to believe. Is there a setting update or way to check this?



victron
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1 Answer
Jaco Reinecke avatar image
Jaco Reinecke answered ·

Hi,

If the BMV is properly configured for your bank, then it is more accurate. The reason I gathered doing my own research, is that the BMV uses a shunt, which is more accurate to calculate the SOC, than working on volts only.

For example, on my 16x 150 cells, I have set the BMV as follows, and it is as close as I can get it to reflect the correct SOC, based on seeing 100% SOC when amps into the batts are just about zero.

Settings Set:
Bulk : 54.6v
Float : 53.4v
Charge: 70amps

BMV Charge Efficiency: 99%
BMV Peukerts Exponent: 1.05
BMV Charged Voltage (0.3% below Absorption) : 56.7
BMV Tail Current: 2% (~2 to 4%)
BMV Charged Detection Time: 3 (~2 to 5 min.)

Sync voltage to be about 0.2 to 0.4 below absorption voltage.
Configure the tail current parameters so it syncs reliably.

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