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randy-putnam asked

Proper cable wiring for BMV 712 shunt and MPPT on parallel LFP batteries

My boat’s house bank has 2 100AH Battle Borns wired in parallel and I’m installing the BMV712 smart shunt today. I will connect the “battery” side of the shunt to the negative post of the “back” battery. The loads are going from the “front” negative post of the other battery to a bus bar. In my previous house bank I had always connected the positive lead on the MPPT and plug in charger to the front positive post and the negatives of the MPPT and plug in charger to the negative post of the back battery for balanced charging. If I keep this configuration with the new LFP house bank will it interfere with accurate readout from the BMV712?

BMV Battery Monitor
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Paul B avatar image Paul B commented ·

I think a wiring diagram of how you propose to do this would be helpfull, just for clarity. as your description is confusing/ not clear maybe incorrect

I will connect the “battery” side of the shunt to the negative post of the “back” battery. The loads are going from the “front” negative post .


Please supply a wiring diagram as all negative loads should come off the load connection on the shunt.

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randy-putnam avatar image randy-putnam Paul B commented ·

Thanks, Paul. I figured it all out once I started the actual install on the boat last week. Prior to the new install I had everything connected to the battery posts. Now all leads go to and from a pos/neg bus bar. Here’s the set up prior to installing the 2 Battle Born 100AH batteries in parallel. The “back battery” is strapped in to the back rear hold down straps and the only negative connections to the “back” (battery only) are the cables going to the negative of the “front“ battery, and the “battery” side of the shunt. The bus bar connects the + and - leads from/to the main battery switch, grounds, MPPT, Orion 12-12/30 and the IP67 charger. Everything works fine.

b6a945f3-217d-4d9a-8379-918afee8712a.jpeg

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Paul B answered ·

good to here you got it all sorted, a tidy battery box and connections also helps a lot

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