Mixed panels

[Skidlm]

Hello. I have 2 Furrion solar panels 165w each on my roof with a 50a Furrion charge controller. I know I can add a couple more panels on the controller . As I look at the specs for the current panels, one was factory installed and one dealer installed and I see mismatched specs. Panel one is 165w, vmp18.7v, lmp 8.82a, voc 23.12v, lsc 9.49a. Panel two is 165w, vmp 19.4v, lmp 8.5a, voc 28.83v, lsc8.91a. My question is can I add two non-Furrion 180w panels:

Open Circuit Voltage Voc (V)	21.6±5%
Max Power Voltage Vmp (V)	18±5%
Max Power Current Imp (A)	10±5%
Short Circuit Current Isc (A)	10.5A
Solar Cells Efficiency	21.2

I know ideally one shouldn’t mix if possible and there will be some system loss but are these proposed panels within standard since nothing matches?

[acoleman43]

Hello. I have 2 Furrion solar panels 165w each on my roof with a 50a Furrion charge controller. I know I can add a couple more panels on the controller . As I look at the specs for the current panels, one was factory installed and one dealer installed and I see mismatched specs. Panel one is 165w, vmp18.7v, lmp 8.82a, voc 23.12v, lsc 9.49a. Panel two is 165w, vmp 19.4v, lmp 8.5a, voc 28.83v, lsc8.91a. My question is can I add two non-Furrion 180w panels:

Open Circuit Voltage Voc (V)	21.6±5%
Max Power Voltage Vmp (V)	18±5%
Max Power Current Imp (A)	10±5%
Short Circuit Current Isc (A)	10.5A
Solar Cells Efficiency	21.2

I know ideally one shouldn’t mix if possible and there will be some system loss but are these proposed panels within standard since nothing matches?

You can certainly add any panel to any array. However, some of your panels will not be efficient.

For example if you have 2 different panels wired in parallel, one panel Voc is 21.6 and the other Voc is 23.12, the array Voc will be 21.6 (the lowest of the 2 panels). Thus the panel with 23.12 Voc looses some efficiency in the array.

This also applies when wiring panels in series. If one panel has Imp of 10A and the other panel Imp is 8.82A, the array Imp will be 8.82A.

I hope that makes sense.

So, if you are using differing panels in the same array, try to match the voltage and current output as closely as possible to keep from losing too much energy potential.

[KSC_Travels]

In addition to these comments above, you will need to check the specs on the Furrion controller (max input voltage & amps specifically) and have an idea of the cable gauge (probably 10awg?) going to the controller from the panels.

Not sure how the two panels are currently wired (series or parallel) - but my guess is that you can probably set up a 2-Series 2-Parallel (2S2P) array and probably stay within the limits of your cables and controller. You would need to verify of course.

[Skidlm]

Attached how the Furrion panels are wired now. Furrion recommends their panels in series. The controller is the 50A Furrion controller which supports 4 165w or 4 195w Furrion panels and is wired with 10awg. Do I wire the two non-Furrion panels to be added still in series then or differently?

[Jlawles2]

That appears to be Parallel wiring. Series wiring would be controller to panel 1, panel 1 to panel 2, then panel 2 to controller. Panel 1 to panel 2 would be opposing poles (positive to negative).

[acoleman43]

If you have the 50a MPPT from Furrion it states up to 50A and 135V from the solar array.

Given this, and if it were me, I would wire the panels in series-parallel. Meaning you would take 2 of the panels and wire them together in series, then take the other 2 panels and wire them together in series. Then take your 2 sets of panels and wire them together in parallel. This will keep you current and voltage within the MPPT limits and, in my opinion, give you the most efficient setup.

[Skidlm]

acoleman43, if my batteries are wired in parallel does changing the panel configuration to series-parallel affect that? This all still a 12v system? Thanks

[howson]

acoleman43, if my batteries are wired in parallel does changing the panel configuration to series-parallel affect that? This all still a 12v system? Thanks

Mark's ( acoleman43 ) not online so permit me to jump in and answer.

The configuration of your panels has no affect whatsoever on your 12V battery bank.

Remember that the solar array's output goes to the solar controller's PV input. The output of the solar controller is still connected to your battery bank as it was before (no change whatsover).

[Skidlm]

Thanks@howson. The two 165w Furrion panels having different configurations which I didn’t expect has thrown me for a loop and then adding in 2 more of another brand, albeit same output configuration just added to my confusion. Thanks to all of you - I am learning a lot. I’m rewiring and fusing most everything the dealer added and installing cutoffs as appropriate. Appreciate your expertise.

[Jlawles2]

Skidlm As mentioned by Howard, the solar system takes input wattage regardless of the voltage and converts it to the necessary voltage and amperage to charge the batteries. Think of the solar controller as a battery charger that plugs into the wall (it's just a bit more complicated). It takes one voltage and converts it into another, the main difference is the solar controller is DC-DC.

[KSC_Travels]

Skidlm

I came across this excellent article from Explorist Life. It explains well, I think, the considerations. Great diagrams too.

[acoleman43]

acoleman43, if my batteries are wired in parallel does changing the panel configuration to series-parallel affect that? This all still a 12v system? Thanks

I'll repeat Exactly what Howard and Joseph said

The solar charge controller will convert the voltage coming form the solar array into the voltage required for you battery bank (12v). That's why you need a solar charge controller (like the Furrion MPPT solar charge controller you currently have).