I have a Kodak OG7.2 with 3xHubble 5.5kw batteries and 2x6series 550w JA solar panels. i only get to generate about 3.5KW from the solar panels. if i look at the watch power app there is a 1.2 to 2 kw difference between PV1 and PV2. I have swapped the 2 string but the result still stays the same. where PV 2 is the highest out of the 2 strings. what could be the issue?

13 hours ago, Johan Meintjes said:

the result still stays the same. where PV 2 is the highest out of the 2 strings.

I can only think that there is something wrong with MPPT1; some sort of hardware problem. I can't even imagine what that is. Perhaps one of the shunt resistors is not making proper contact, so the MPPT thinks that the current is twice what it actually is. But as I type this, that doesn't make sense.

Do the reported PV voltages seem to be right?

Next would be PV currents, but you likely have to adjust for battery voltage versus PV voltage, and possibly also for load current. But you can probably compare reported solar charge current with similar loads, swapping the strings. Perhaps use a clamp meter to measure PV currents and compare with the reported current, using MPPT2 as a reference.

Edit: Though you should boil a kettle or add some other AC load to make sure that it's not just the fact that the battery can't take any more charge current. It could be the case that MPPT2 takes more of the available solar charging duty for some reason, though it does seem unlikely.

Edited August 9, 20233 yr by Coulomb