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Egon Brainparts avatar image
Egon Brainparts asked

BMV 712 reporting incorrect current, watts, SOC, etc.

Hi,

I've been following several threads from this forum regarding technical issues with the BMV 712. I've had the monitor for quite some time and it has never worked right. It has always reported everything incorrectly except for voltage. I have confirmed the wiring is correct from the shunt and replaced the rj12 utp cable, which solved several other users issues, but not mine.

The most strange things are that it always displays a current of about 10.5A without positive or negative denomination and does not discernably change when I either add or remove other loads. It also reports watts at about 185 regardless of my activity. It has never synced correctly although I have fine tuned settings with my smartsolar mppt. I really at this point have no clue what the story is and although my system runs fine, I would like the BMV to do more than just be a voltmeter.

The unit has no issues being powered on and or taking feedback from the app. I am curious if there are any voltsge or current measurements I can take at the shunt or from the utp wire to confirm where the source of the issue lies.

Happy to answer questions. Just need some help.

BMV Battery Monitor
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2 Answers
Egon Brainparts avatar image
Egon Brainparts answered ·

System is 12v with 300ah of Battleborn LiPo4 batteries, Victron Smart Solar 150/100 mppt, 12/2000 80a multiplus compact installed in a truck camper. Batteries charge normally everyday via solar and 99% of the time get thru absorption to float. Inverter and all DC electrical works normally and has for over a year running.

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ben avatar image
ben answered ·

A BMV without a working current measurement is almost useless; sorry to hear you're having trouble.

The single most useful measurement you could take would be to put a clamp DC ammeter on the wire going to the shunt and see what current is actually flowing. It's pretty common for the shunt to be miswired, even though I know you say you've checked it.

If you don't have one of those and can't borrow one, or if you do see normal looking current with the meter, then you'll probably have to reach out to your dealer and get help started that way.

(You could take pictures of your wiring for us to look at here, but sometimes those are hard to interpret.)

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