I have a recently installed a Smart Solar 150/45 connected to two 340w 24v panels wired in series. The controller then feeds into two AGM 115Ah @ C20 12v bank in parallel.
Initially when everything was hooked up the PV input only saw ~0.6V, after going through the wiring I couldn't see anything blatantly wrong. I disconnected the PV wires going into the terminal of the Smart Solar 150/45 and tested the ends with a multimeter and saw ~80V. I now have removed the charge controller and directly hooked it up to the two panels directly and I am now seeing a higher voltage on the terminals, but the voltage is ~0.1V less than the battery voltage (~12.6V). I understand that the PV voltage has to be 5V higher than the battery voltage to start charging, but I don't understand why the PV voltage is consistently coming around the battery voltage even though the open circuit voltage is ~80V.
Could this be a firmware issue as I updated the charge controller to 3.13 when installing?
Apologies if this has been asked before but I haven’t been able to find this by searching. Any insight into why this is happening and anything I can do to stop it would be very much appreciated.