Mixing solar panels: stats close enough?

[Jonathan123]

I’ve got 6 100 watt panels and want to add more from another brand. Are these numbers compatible or too far off?

Existing Back 40 panels:



Proposed additional Rich Solar panels:

 

[sunshine_eggo]

Vmp is the most critical in parallel. 18.0 vs 18.6 is good.

Imp is the most critical in series. 5.55 vs. 5.78 is good, though all panels in series will run at the LOWEST current of all panels in the string.

4% penalty in series
3% penalty in parallel

Looks good to me either way.

 

[MisterSandals]

Mostly out of curiosity, what are you doing with so many 100W panels? What SCC do you have and how are you connecting them (series? parallel? mix?)?

 

[sunshine_eggo]

AGM to LiFePo4 conversion

I’ve got an RPS Solar water pump with depleted batteries and am replacing them with LiFePo4 and also need to increase capacity. I’m having trouble calculating my energy needs for this due to the variability of the pump draw and am hoping to get some clarity from you all. Location: Maine PV...

diysolarforum.com

 

[Jonathan123]

Thanks for the repost @sunshine_eggo. Correct, I’ve got a 24v battery bank powering a 220v water pump via single all-in-one charge controller/inverter supplied by RPS Solar. The panels (connected in series) haven’t been getting enough sun so I’m moving them but I think I need to add panels and maybe battery capacity too. We don’t actually use the water pump all that much - off-grid cabin toilet, shower, sink - but the standby power draw and lack of input has been a problem.

 

[Jonathan123]

Vmp is the most critical in parallel. 18.0 vs 18.6 is good.

Imp is the most critical in series. 5.55 vs. 5.78 is good, though all panels in series will run at the LOWEST current of all panels in the string.

4% penalty in series
3% penalty in parallel

Looks good to me either way.

Thanks!

 

[Rocketman]

Just wanted to make sure…

In going series into your. AIO - you verified that you will not input too many volts - used the Voc for that calculation and left room for the panels to get cold and their voltage to rise…

 

[Jonathan123]

Just wanted to make sure…

In going series into your. AIO - you verified that you will not input too many volts - used the Voc for that calculation and left room for the panels to get cold and their voltage to rise…

Good question. Yes I checked in with RPS Solar on how many panels I can add and they verified I've got lots of room.