Battery Monitor 712 not reporting input current from Aux/Starter Battery

DIY
, , ,
1

Hi,

I am beginner and have a question regarding monitoring the charging current from a Aux/Starter battery on a BMV-712 Smart

Setup:

BMV-712 set up on boat. Primary House Battery (260Ah) and a Starter Battery set up as in the quick start guide. Below

BMV-712 Smart set up
BMV-712 Smart set up1920Ă—2550 214 KB

2x MPPT 75-15 provide the charge to the house battery and I see the charge current on the BMV.

The alternator directly charges the starter battery and a VSR enables charging of the house battery from starter battery when a certain voltage is reached.

Question: I do not see the charge current from the alternator/starter battery on the BMV. Is this correct ? Even with the VSR on.

Note: The BMV is not currently synchronised and reporting 100%. I haven’t seen a complete discharge cycle.

Thanks,

Simon

2

Then probably the negative sides of the two batteries are directly connected, and not as in the drawing. I don’t see another explanation.

1 Like
3

The BMV only measures the voltage of the aux battery. Have you told the BMV that the 2nd connection is another battery.

The reason you are not seeing the charge current from the VSR is you may not have the common ground or chassis/hull ground right.

See this DIY FAQ

See this FAQ about correct 200% synchronisation settings.