Bmv 712 SOC not reacting to solar input

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mojo asked Sep 12, '19

Bmv 712 SOC not reacting to solar input

I have a recently installed victron lifepo4 set up 4 x 150 ah 24 v system new bmv 712 new smart solar mppt 250\60 controller.

My query is that although the mppt is operating correctly and giveing a good input from 3 245w Panasonic solar panels wired in series , the 712 bmv soc display is constantly falling in value despite the battery voltage never really dropping below 26.4 volts and has reached a high of 28.4 v

Should this re-set the soc to 100% or am I missing something?

Any input very welcome

MPPT Controllers

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murph answered · Sep 12, 2019 at 01:15 PM

Is your MPPT's negative connected via the BMV's shunt? It sounds like you have incorrectly connected it directly to the batteries. You must only have batteries on the battery side of the shunt, with all loads and chargers on the other side.

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Modifications Space

Node Red Space

Answer 1 · 2019-09-12T13:12:16Z

JohnC answered · Sep 12, 2019 at 01:12 PM

Hi Mojo. It's likely your mppt has been wired to bypass the BMV shunt, so it won't get measured. There should only be one wire hooked to the batt -ve, and that's the one to the shunt. The mppt -ve should be wired into the 'Load' side of the shunt. It's not a 'load', but that's where it must go.

https://www.victronenergy.com/upload/documents/Quickinstallsheet_BMV70x_part1_2.pdf

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Answer 2 · 2019-09-12T14:45:26Z

mojo answered · Sep 12, 2019 at 02:45 PM

Ok thank you for the replies , I’ll look into it , I’ve lost confidence in my installer so may have have to get some help from another source

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Answer 3 · 2019-09-12T14:53:11Z

mojo answered · Sep 12, 2019 at 02:53 PM

Murph

On investigation the mppt negative is connected directly to the batteries via a connection post. So for clarity it needs to be connected to the other side of the shunt ?

And what should I disconnect before doing this ?

Mojo

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Answer 4 · 2019-09-12T17:43:30Z

mojo answered · Sep 12, 2019 at 05:43 PM

Murph / John

All sorted thanks to your input, I managed to do it myself .

Regards Mojo

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