question

straycat avatar image
straycat asked

100/50 MPPT showing incorrect battery voltage

Hi

I have 5 panels on a sailing boat with 5 MPPT controllers (1 per panel). One of the MPPT controllers (older one) is showing a voltage around 13.28V where the others and the BVM are showing 13.59V. I have checked the voltage at the MPPT using a multimeter and it also shows 13.59V.

Resetting the system does help, but only temporarily. The MPPT only shows the correct voltage for a few minutes. Does any one have any suggestions?

I don’t think it’s cables but I will check (again). The faulty MPPT controller has a larger negative cable to the others, but I doing think this is the issue.


MPPT Controllers
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2 Answers
JohnC avatar image
JohnC answered ·

Hi @Straycat

From another post it appears you may have a GX device too. If so, consider invoking DVCC (at least the SVS part). This will pass on a selected V, in your case the BMV's battery V, to all the mppts. So then they will all control to that one 'global' V and ignore their own. This helps eliminate the effects of individual unit inaccuracies and wiring issues with V at high currents.

DVCC is explained in the GX manual.

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oxy avatar image
oxy answered ·

I started having incorrect battery voltage on SmarSolar MPPT 250/100 rev2 too! Some degradation in either the software or HW, as voltage at terminals measured by voltmeter is correct.

I actually tried to workaround it with DVCC in GX. It sort-of works, but then a different issue appears:

https://community.victronenergy.com/questions/238355/setting-dvcc-controlling-bms-to-none-results-in-bm.html?childToView=273331#answer-273331

Maybe you found out how to fix the cause - make SmartSolar charge controller see correct voltage again?

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