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marc-mcfly avatar image
marc-mcfly asked

Pylontech low charge current (charges just on one phase)

Hi,

I do have following Setup:

  • 3x MultiPlus-II 48/3000/35-32 configured as 3 phase system (multiphase regulation set to "sum of all phases" )
  • 3x Pylontech US3000C as battery bank
  • Solar AC coupled 5.5kw peak on phase L1 (old system from 2012 limited to 4kw max output)

The Problem now is that the Pylontech batteries are only charged with about 32A from the Multiplus on phase L1. Maximum i have seen was 35A. The other 2 inverters seem to not charge the battery. This then results in lot of excess solar still feed into the grid instead of the battery. Discharging however works fine. Then all 3 Multiplus activate and discharge with about up to 110A maximum.


The charge current limit of the battery says 111A in the cerbo gx as you can see in the picture. So that cant be the problem. Also as a test I change the ac solar from L1 to L2. Then only the Multiplus on L2 charges the battery. Is this problem maybe some kind of configuartion issue ?


victron.jpg victron-pylontech-limita.jpg

Multiplus-IIESSPylontech
victron-pylontech-limita.jpg (87.0 KiB)
victron.jpg (143.6 KiB)
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Alexandra avatar image Alexandra ♦ commented ·
Check the charge current set for the charger tab.

And what input current limit have you set?

Have you tried seeing what happens when multi phase regulation is off?


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2 Answers
Mike Dorsett avatar image
Mike Dorsett answered ·

If all your solar charging is on one phase, then the other 2 phase inverters have no input for battery charging.... the cerbo is expecting the other 2 inverters to have identical solar input, so the allowed charging current is split between the 3.

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marc-mcfly avatar image
marc-mcfly answered ·

Ok, that would explain the issue. But I thought the other inverters would simply pull the power on L2 and L3 from the grid to charge the battery if there is excess solar power on L1. So the grid meter is always kept close to zero. This is also mentioned in the ESS manual.


So basically with a single phase pv inverter there is no chance to get all 3 mutis to charge the battery ?

ess-3-phase.jpg


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