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coltarkdm avatar image
coltarkdm asked

Incorrect Shunt Connection?

It is very clear that there should only be one connection from the negative battery terminal to the supply side of the shunt. That said, the installation diagram for my Victron Multiplus 3000/70/24 indicates that the T-Sense cable should be run from the negative battery terminal to the T-Sense input on the Multiplus and that is how I wired it. Now I'm thinking that is incorrect and that the cable should be connected to the load side of the shunt. Ever since I completed my solar install, I haven't felt like my BMV712 has been displaying correct SOC and I'm hoping this change might help. What do you think? I have 4-100ah Battle Born in 24v configuration..

BMV Battery Monitor
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2 Answers
Stefanie (Victron Energy Staff) avatar image
Stefanie (Victron Energy Staff) answered ·

No. It's correct the way you wired. The T-Sense has nothing to do with SoC.

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coltarkdm avatar image coltarkdm commented ·

Thank you Stefanie!

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Daniël Boekel (Victron Energy Staff) avatar image
Daniël Boekel (Victron Energy Staff) answered ·

Hi @ColtarKDM

What are the settings in you BMV? (peukert factor and charge efficiency)

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coltarkdm avatar image coltarkdm commented ·

Thanks for helping me. Here are my settings.

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Daniël Boekel (Victron Energy Staff) avatar image Daniël Boekel (Victron Energy Staff) ♦♦ coltarkdm commented ·

ok, and in what way is the SOC incorrect? is it too high or too low? or does it reset to soon?

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coltarkdm avatar image coltarkdm Daniël Boekel (Victron Energy Staff) ♦♦ commented ·

Do my settings look good?

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Daniël Boekel (Victron Energy Staff) avatar image Daniël Boekel (Victron Energy Staff) ♦♦ coltarkdm commented ·

in what way is the SOC incorrect? is it too high or too low? or does it reset to soon?

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coltarkdm avatar image coltarkdm Daniël Boekel (Victron Energy Staff) ♦♦ commented ·

SOC has a tendency to read low compared to actual voltage. I use the following chart as a guide.

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Daniël Boekel (Victron Energy Staff) avatar image Daniël Boekel (Victron Energy Staff) ♦♦ coltarkdm commented ·

That table is probably a guide, but actual voltage vs SOC will depend on a lot of things, like load / charge, temperature.

The only way to know if the SOC is correct, is to do a full charge, followed by a full discharge, and see how many Ah came out of the battery when empty.

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