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barney9304 avatar image
barney9304 asked

Hi, this is my bmv 712 at this moment. The second picture is my settings for the bmv. Why is the soc so wildly out?


I have 754 amps at C20 of tubular 2v deep cycle batteries, to charge these I have 530w of solar and a 5kw diesel generator. I have a 12/3000/120 inverter charger from victron and a bmv 712 both only a couple of months old.

I can adjust most things with victron connect either with bluetooth or with a mk3 usb. The multiplus is wired correctly with the correct victron spec wiring as is the bmv all negs go to the correct side of the shunt etc.

setup
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3 Answers
dazey77 avatar image
dazey77 answered ·

Why do you think SOC is wrong? Battery voltage under load is not a reflection on SOC. There is nothing in the screenshots that says SOC is incorrect.

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barney9304 avatar image
barney9304 answered ·

I am using 15 plus amps which is not a big load but 83% SOC but the voltage is showing 50%? C20 rate is 35 ish amps, I take it the SOC runs on the C20 rate so that's why it's not as low as the voltage? Voltage is the overriding factor for when to charge by genny?

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dazey77 avatar image
dazey77 answered ·

As I said, voltage isn't a measure of SOC. To use voltage in this way you need to disconnect all loads, leave battery voltage to recover, then use that voltage as a SOC indication. The whole point of the BMV is that it provides a decent estimation of SOC that isn't possible using voltage. Otherwise we would all just use volt meters.

You can use SOC to trigger your genny, just use the relay output of the BMV.

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