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dansonamission avatar image
dansonamission asked

Can't charge more than 95% MP-II Pylontech

Hello

Since updating the firmware on the multiplus-II 48/5000 to 508 we haven't been able to charge our pylontech batteries past 95% using solar. (2x 250/85 VE MPPT's on ve.can) Plenty of solar available as 2kw is being exported. The cerbo is on 3.00

The available current limits reported by the batteries are much higher than what is being put into the batteries. Currently, it's reporting CCL as 44amps, but no charge is happening. Usually, this would drop to zero when at 100%

There are also some differences in battery levels being reported on VRM. The battery section on the dashboard shows 92% but the multiplus line listed underneath shows 95% The voltage is being reported as 52.4


Many thanks

Multiplus-IIMPPT SmartSolarpylontec
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2 Answers
Alexandra avatar image
Alexandra answered ·

@dansonamission

Usually when feedback is on CCL is ignored anyway on the battery. So that is not the issue.

What you should start with is a firmware update on all components. I see the MP2 is up to date but it Cerbo is not is the mppt correct? Top dollar bet is it's the Cerbo being so far out.

Check everything is programmed according to the Victron Pylon page.

52.v is usually the charge voltage from the inverter so that in theory is the correct voltage. What is the CVL from the battery being reported as?

The other thing that I have seen on some pylons is their SOC drifts. So the battery could also be the issue.

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dansonamission avatar image dansonamission commented ·

Updated to V3.13 on the cerbo, still the same.

Our CVL reported by the Pylons is 53.2V

The mppt are on v3.13

Triple checked everything on the VE pylon page, double check them as well when it was updated to 508 a while ago.

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dansonamission avatar image
dansonamission answered ·

Guessing it's probably to do with this point below, but I don't see why it would start doing it now, unless its got out of sync as we did have 4-5 weeks where the soc was between 20-30%


The battery won't charge to 100%

Also see the question above. The state of charge of the battery is estimated based on the overall voltage and on how well balanced the internal cells are. Because we cap the battery voltage at 52.4V, the state of charge will sometimes rise very slowly once it reaches the mid-90s. This is normal and usually resolves over time.

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Alexandra avatar image Alexandra ♦ commented ·

Then the solution is to set it to keep batteries charged. See if that resolves the issue. Might be something you have to periodically do.

Otherwise, above 90% SOC pylons balance so there should be no issues in that department.

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