Battery Balancer & BMV-712 wiring

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greatlake asked Oct 9, '23

Battery Balancer & BMV-712 wiring

I am using BMV-712 smart battery monitor along with the Battery balancer on my 2x 12V battery banks (in series, 24V).
The BMV-712 manual and the quick installation guide say that

the shunt is the first and only thing that should be connected to the battery negative.

Note that there should be no other connections on this side of the shunt or on the negative battery terminal. Any loads or chargers connected here will be excluded from the battery state of charge calculation.

Does this also apply to the battery balancer or may I connect it like in fig.1 with a wire to the negative battery pole directly?
Or will the measurement become inaccurate so that I need to do the wiring like in fig.2?

Thanks in advance.

BMV Battery Monitor wiring Battery Balancer

battery-balancer-wiring01.png (138.6 KiB)

battery-balancer-wiring02.png (139.0 KiB)

2 |3000

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kevgermany answered · Oct 09, 2023 at 08:13 PM

There's so little current draw that it won't affect readings significantly. Mine's wired direct to batteries, ignoring the shunt.

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Modifications Space

Node Red Space

Answer 1 · 2023-10-10T07:43:53Z

greatlake answered · Oct 10, 2023 at 07:43 AM

Thank you very much! When I connect the balancer to the negative terminal of the battery I can use three wires of the same length which is another advantage to maintain accuracy of the measurement.

2 |3000

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