Combining different size solar panels on camper

Question

question

durovenia asked Mar 22, '22

Combining different size solar panels on camper

Hi all!

I currently have 2x 175W solar panels from Victron on the roof of my camper (Vmpp = 19.4, Impp = 9.03, Voc = 23.7, Isc = 9.89). I have them in series connected to a 100|30 MPPT from Victron. I have limited space on my roof but would like to extend my grid with one or two 55W panels (Vmpp = 18.8, Impp = 2.94, Voc = 22.9, Isc = 3.22). What would be the best way to connect them to my grid?

I understood that It is not advised to mix different panels - especially in series (high-efficiency loss), but parallel should work (with only a slight loss), right? Or am I missing something? Could you help me sort out the right method in case of:

2x 175W + 1x 55W
Can I put all the panels in parallel and still run the same MPPT controller, or do I need to put the single 55W panel on its own controller. If so, which one should I go with (hopefully able to use with the same app).
2x 175W + 2x 55W
Should I parallel them all or serie-parallel (175Ws and 55Ws separated) and run them on the same MPPT controller, or do I need to run both sets from their own controller? If so, which one should I go with (hopefully able to use with the same app).

I highly appreciate your help.

Cheers,

Joy

MPPT Controllers Solar Panel smart solar set-up help solar sizing BlueSolar PWM

2 |3000

Attachments: Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

Modifications Space

Node Red Space

Answer 1 · 2022-03-22T19:46:14Z

hjohnson answered · Mar 22, 2022 at 07:46 PM

If I was you, I'd just add another MPPT. The 75/15 is cheap enough, and the 75/10 even cheaper. That will work much better. Just get the SmartSolar and you should be good to go.

2

2 |3000

Attachments: Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

durovenia commented · Mar 23, 2022 at 08:03 AM

This will only work with two extra 55W panels in serie right? Can imagine that only one will not supply enough voltage to get the MPPT running properly. Or will this not be a problem?

0 ·

kevgermany ♦♦ durovenia commented · Mar 23, 2022 at 08:00 PM

Depends on the panel. Check the specs of the panel. You need actual battery voltage +5V from the panel for the charger to start. So on a 12V battery system you need a panel setup that generates at least 18V, preferably 19 or more. The one you mentioned above will work series or parallel. But I'd wire 2 in series.

0 ·

question