Low solar power output

[jamiegreen]

Prior to upgrading to 48v, I ran a 24v system, with the solar capped to 60a. 8x 265w panels wired in 2s4p. Whenever the sun was out the controller always seemed to be capped at 60a (1.6kw) or there abouts.

Now on 48v with a much higher PV input, I seem to be getting less power. I mean, it's hot this past week, annoyingly hot but I'm sure the panels used to do better than around 1.1-1.2kw back on 24v. On the other hand on a cold day I've seen much higher outputs on 48v, but only.. once I think.

I'm wondering.. is my issue the PV input voltage maybe? If I recall it's about 60v in the sun, the MPPT seems to lock on around 58v most of the time. Victron recommends +5v over battery voltage though.. which it's just about. It's lifepo4 so around 54v.

Do I need to add another panel and make 3s? that would be kind of annoying given my panel layout but needs must if that may be the issue. Also the random dip in power is just me temporarily turning solar off.
Any ideas?
Thanks

 

[Mattb4]

Please give your panels and your SCC (or AIO) ratings. Likely you can get a better setup with maybe 4S2P. Should not be all that hard to rearrange your wires since all your panels are in a block and ground mounted.

 

[jamiegreen]

Please give your panels and your SCC (or AIO) ratings. Likely you can get a better setup with maybe 4S2P. Should not be all that hard to rearrange your wires since all your panels are in a block and ground mounted.

Unfortunately not possible to do 4s, as much as I'd like to. They are 37.5v VOC panels, and my controller is 150v max, a bit close to comfort for my liking.

 

[Mattb4]

Yeah with 150Voc limit from SCC and your panels Voc of 37.5v you are a bit restricted. If you can add 1 more panel you could do a 3S3P setup but losing 2 panels to do a 3S2P setup would be quite a hit. However a 2S4P setup (as present) is marginal voltage at Vmp for a 48v LiFePO4.

That said never hurts to check all connections to double check that something else is not reducing production.