question

Lou Cetrangelo avatar image
Lou Cetrangelo asked

BVM-712 Current not Accurate

My set up is 2 Battleborn Lithium batteries connected in parallel for 200 ah @ 12vdc. Victron Solar Charge Controller 100/50, Victron MultiPlus 3000 ah /12v, Color Display and a Victron BMV-712 battery monitor. This setup is in my 5th wheel RV.

The issue is that the BVM-712 appears to indicate a much higher current discharge while just about everything is turned off. While it is sitting there with everything off the draw is about 2 amps. After 3 days the battery monitor is saying that the battery bank is down to about 50%.

At this point the battery voltage is down from 14.7 to 13.37 volts. On a Battleborn chart it shows that to be about 95% full.

Suspecting an inaccurate reading I disconnected the cable from the negative terminal of the battery to the shunt. I measured the current between the end of the cable and the shunt where it would normally connect. It was 0.37 amps.

I double checked the shunt by removing it and turning it over. It said 500 amps 50 mv which is what my meter is set for.

I know the meter is supposed to be very accurate. Am I doing something wrong?


BMV Battery Monitor
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3 Answers
Matthias Lange - DE avatar image
Matthias Lange - DE answered ·

2A over 3 day's (72h) are 144Ah (2A x 72h)-> around 75% discharge.

With lithium batteries you can't say "voltage x = SOC y"

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JohnC avatar image
JohnC answered ·

If there's a 'zero error' in the BMV it can be corrected, see the manual. Of course isolate one side of the shunt to check that.

Standby current of the Multi 3000 alone is listed 20W on the spec sheet, so approaching 2A @ 12V.

I'd believe the BMV..

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Lou Cetrangelo avatar image
Lou Cetrangelo answered ·

It looks like I fixed it. I did a full reset on the battery monitor and then pput in the recommended settings from Battleborn. When in float mode the battery monitor is showing 100% for the last 12 hours. With the RV main DC switch on there is a small discharge but the trickle current during float cancelers that out. When I unplug shore power and turn off the main RV dc switch there is zero discharge showing.


I should have done a reset at the start. There might have been some incorrect settings when I got it. Anyhow it is working great now.

Thanks for your help.

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