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bob-kones avatar image
bob-kones asked

BMV 712 Charging Start Battery Docs

Hi Guys!

I installed the BMV 712 last year. It's primary purpose is to monitor coach batteries. I also have it wired to monitor the starting battery. I seem to recall that it could actually charge the starting battery as well when it dropped below a certain value although it was a low-amp charge, which is fine.

I can't seem to find any documentation on this. Last year I was sure I saw a wiring diagram from Victron for implementing this but can't seen to find *anything* related to documenting this feature. If anyone can point me to a link or in the right direction I'd appreciate it.

BMV Battery Monitor
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seb71 avatar image
seb71 answered ·

The purpose of the BMV-712 is to monitor the charging state of the batteries, not to charge them.


If you want to charge the starter battery from another battery, use a DC to DC charger.

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Matthias Lange - DE avatar image
Matthias Lange - DE answered ·

You can setup an alarm or switch a relay if the voltage of the starter battery drops below a set value but the BMV is not a charger.

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bob-kones avatar image
bob-kones answered ·

Odd....I could have sworn I saw something about charging a starter battery, albeit, with a minor trickle-type charge. I also installed a 100/50 AMP solar controller at the same time. Perhaps it was that? I was sure I sawa a wiring diagram, at the time, for doing it with a disclaimer that it was a very limited charge.

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seb71 avatar image seb71 commented ·

The answer I got from from Radio Yerevan:


It is true that it's a very small current, but it is not charging, it is discharging.


:)

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pwfarnell avatar image
pwfarnell answered ·

Some of the Victron Multiplus inverter / chargers have a trickle charge connection for the starter battery taken from the house battery.

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