I have a MPPT250/100 on my solar panels (correctly sized), with which I go to 24V lead-acid batteries and from there I go to a MultiPlus Compact 24/1600/40-16. Using a Raspery with Venus Software I set ESS so that the batteries always remain charged except in the event of a grid failure.
I have 8x 12V batteries:
-4 parallel
-2 serial (using a Victron balancer)
Each has 65Ah 12V,so it‘s a total of 260 Ah, 24V
I know, using those in parallel isn‘t perfect…
The exceeding power I feed back into the grid via MultiPlus.
Now, when the solar power exceeds the power of the MultiPlus, the charge voltage at the MPPT starts to vary in around 5 seconds cycles strongly, sometimes it goes down towards almost 0 watts and then jumps back up to around 1650W.
I have now tried to limit the maximum charge current at the MPPT, then this no longer happens, but in certain cases, of course, I no longer have the optimum power of my panels.
Does anyone know where the problem could be that the charging power always starts to fluctuate so in the limit range (batteries are of course 100% full)?