question

Mike B avatar image

BMV712 connection for midpoint voltage

I have 6 Firefly L15 (4V) batteries. I would like to wire these in series(3x4V) /parallel to have 12V/ 900Ah. I am installing a BMV712, and would like to have Midpoint voltage monitoring. Please show a diagram of how to wire this configuration. The "Quick Start" guide does not show a diagram which seems to match.

Thank you

BMV Battery Monitor
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3 Answers
Mike B avatar image

OK, 2 opposite answers, can we get some further clarification from Victron?

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The answer has nothing to do with Victron - Victron do not make the batteries being discussed.

But this is not a complex matter...

If the link between the 2 cells can somehow be physically accessed to attach a wire for the mid point monitor (ie. if they are external), then yes it will work. But if you can't then it won't...

Basically all batteries are internally made up of separate 2v cells, but you typically can't access the links

Hi Mark, looks like a midpoint reading is possible. The Firefly 4v batteries consist of 2 /2v cells connected externally with a connecting bar. Should allow the midpoint monitoring, correct?


In that case yes - it should work fine.

vineyardgray avatar image

Each Firefly 4v battery are actually two 2v cells externally connected with a series busbar. It should be possible to get to the 6v midpoint.

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Mark avatar image

Hi Mike,

Sorry but with those particular batteries in a 12v setup you physically can't access the midpoint (6v), so midpoint monitoring is not posible The voltage at the link terminals/cables would be 4v & 8v.


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