Hi, first, we are using Ep**er Solar Charge Controllers because I got 2 of them for the price of 0.75 victron charge controllers.
Now the problem: I got 12 old TrinaSolar modules, grouped them into 4x3 Modules and connected 2 parallel strings of 3 series modules per charge controller to stay in the 150Voc limit.
When not connected to anything, the parallelized strings read ~120Voc, in the moment when I connected the breaker to the charge controllers the voltage dropped down to ~20 to 30V. The controllers are MPPT charge controllers connected to a 2S2P bank of 120Ah 12V batterys.
I am using a similar setup with 6 instead of 12 modules and one instead of two charge controllers at home, only difference is that I have a different charge controller (a MakeSkyBlue one) and that as usually expected the voltage only drops a little when I connect the charge controller.
Does anyone has experienced a similar behaviour before?
Btw: Both stringpairs simlutaniously drop down to 20 to 30 volt from 120Voc so I am not sure if I got a matching module problem for both stringpairs (I'd usually expect one stringpair to drop due to a problem but both?)
