Voltage variance between SmartSolar 100/20, BMV712 and multimeter

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corbijn asked Feb 19, '21

Voltage variance between SmartSolar 100/20, BMV712 and multimeter

Hi there,

I am in the middle of setting up my first pieces of Victron gear with my lifepo4 100ah 12v battery.

I love the features and the quality construction but I do have a question.

I am seeing different voltages across my victron gear and readings from a multimeter.

BMV712 reads 13.34v
SmartSolar 100/20 reads 13.33v
Multimeter reads 13.28v

i have taken multimeter readings from various areas. The battery terminals, from the terminal and the shunt and from the mppt terminals. All readings are 13.28v

I have seen comments that there could be an incorrect fuse in the BMV712, but I’m also wondering what could cause this?

I have no long runs of wire and I have checked the crimping on my connectors.

My primary concern is the the mppt charger will stop charging too soon.

Thanks in advance for your help.

BMV Battery Monitor MPPT SmartSolar voltage

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Answer 1 · 2021-02-21T07:05:52Z

Jmarc answered · Feb 21, 2021 at 07:05 AM

0.01v difference between mppt and bmv is negligeable. This is less than 0.1%. Assuming the mppt was charging, its voltage will always be slightly above the BMV.

As far as your voltmeter, unless you know it has been recently calibated, I would assume it is not as accurate as the mppt and bmv.. It is not bad. The difference is 0.5% which is average for low cost voltmeter.

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corbijn commented · Feb 23, 2021 at 06:28 AM

Yeah ok - this is a decent multimeter but it may be off. I will definitely check that. I'm not too worried about the discrepancy between the two victron devices.

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Answer 2 · 2021-02-21T10:03:52Z

marvs answered · Feb 21, 2021 at 10:03 AM

I have a system that includes a CCGX and by using the ESS function, the voltage, current, and temperature that is read by the Shunt is shared and used by all of the connected devices. Look at synching your devices.

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corbijn commented · Feb 23, 2021 at 06:28 AM

I did see that, I will explore more how the option works. Thanks for the tip :)

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seb71 corbijn commented · Feb 23, 2021 at 08:21 AM

DVCC is the one you want for this, not ESS.

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Answer 3 · 2021-03-05T10:47:33Z

marky01 answered · Mar 05, 2021 at 10:47 AM

Are the devices close to each other ? perhaps use VE. Smart networking via Bluetooth

I have a smart solar MPPT and smart shunt, both these devices use VE. smart networking,

The Shunt sends voltage data to the MPPT

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