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greg-cope asked

BMV-700 Amp reading inaccurate

I have a BMV-700 with bluetooth dongle on a Boat. The shunt is wired to the negative feed of the house bank which is 500Ah of LifePO4. The B2 BMV-700 input is to the AGM Starter battery voltage. This used to work okay with a previous FLA house bank (since replaced). There is a 70/15 MPPT controller connected to the LifePO4 and another MPPT(not Victron) connected to the AGM via their own fuses.

I have tried repeatedly zeroing it with nothing connected (ie loads switched off and MPPT fuse removed). A clamp meter and the LifePO4 BMS both confirm zero amps at this time.


The shunt seems very inaccurate. It swings wildly up to +/-7A when nothing is on. Voltage for both house lifePO4 and starter AGM are fine. Yesterday, in rare UK sun, the MPPT was putting in 12A and the shunt read 0 Amps.

What could confuse the Amp reading? Could there be interference on the data cable OR the shunt B1/B2 cables (both are original length and near other cables).

Do I need a new PCB?

BMV Battery Monitoramps
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1 Answer
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seb71 answered ·

There is a 70/15 MPPT controller connected to the LifePO4 and another MPPT(not Victron) connected to the AGM via their own fuses.

Where are the negative wires connected?

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Related Resources

Victron BMV battery monitors product page

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