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shanon asked

Multiplus 2 DC Bus voltage measurement inaccurate

Hi Everyone,

I have a Multiplus 2 48/5000 with Pylontech batteries and a Cerbo GX.

The DC Bus voltage that the Multiplus is displaying seems to be about 2 Volts too high even when there is no charging taking place.

I understand Ohm’s Law and how this affects voltage readings.

I’ve verified the voltage readings both at the DC terminals of the Multi and at the batteries with two different DMM’s and this indicates that the Multi is reading the DC Voltage inaccurately.

I’ve checked all connections are clean and firmly secured.

The inaccuracy seems to continue to increase over time.

I’ve heard that returning the Multi to the dealer for recalibration is one option (not sure if it’s correct) and I wanted to ask the community if adding a smart shunt would be a better long term fix?

Regards,

Shanon.

Multiplus-IIdc meter
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Alexandra avatar image Alexandra ♦ commented ·

@Shanon

When you are measuring, is it when there are no loads and no charging? So an idle system.

Does it affect how the battery is charged?

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shanon avatar image shanon Alexandra ♦ commented ·
Yes that’s correct.

It affects how the battery is charged in that it won’t fully charge unless I increase the charge voltage to account for the discrepancy.

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Alexandra avatar image Alexandra ♦ shanon commented ·
If all the firmware is up to date a d youbare not happy then i would advise taking it in or returning it.
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shanon avatar image shanon commented ·
@Guy Stewart (Victron Community Manager)

Can you help please.

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nickdb avatar image nickdb ♦♦ shanon commented ·
Guy is away, and what you need is to contact your supplier for support, there is little here the community can assist you with and you have been given some good advice, so I would suggest the unit is returned for testing, if you have eliminated everything else as a cause.

There is nothing you nor a dealer can calibrate.

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shanon avatar image shanon nickdb ♦♦ commented ·
@nickdb Ok will do.

Thanks Nick.

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0 Answers

Related Resources

MultiPlus-II Product page 

MultiPlus-II Manual

Multiplus-II GX Online Manual

MultiPlus-II 230V Datasheet 

VE.Bus Error codes

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