Batteries only receiving 30a DC each connected to 30a AC shore power

DIY
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1

Hello everyone,

I’m running a Victron MultiPlus 12/3000/120 connected to three SOK 280Ah batteries, and it’s powered by a generator capable of providing 30A at 120V.

The issue I’m facing is that I can only seem to get 30A of charging to each battery. I’ve already set the max bulk charge current to 120A, but the MultiPlus only outputs about 90A total, and I can’t figure out why it’s not delivering the full capacity.

Has anyone encountered something similar or have any suggestions to troubleshoot this?

Thanks in advance for your help!
Jeremy

2

This is likely due to volt drop in the battery feed cables - or even the AC cable from the gen.

  1. If the AC voltage is low at the MP AC inputs, then it cannot achieve full current.
  2. Volt drop in the d.c. cables is the most likely culprit. Are the battery cables getting warm when charging? You can try measuring the DC voltage at the inverter terminals and also at the battery terminals. Volt drop should be <<0.1V at full current.
    d.c. volt drop can sometimes be mitigated by using remote voltage sensing.
3

Thanks for getting back to me Mike!
I was able to get it to hit its peak by turning off the “Weak Ac” setting.
Not totally sure what this setting does and if its need?