question

magnus avatar image
magnus asked

Two solar panels in parallel does not give more power

What's happening here? I have a new Victron Charge regulator (10/75). I also have two 50 W solar panels(one 10 years old and one two years old). When I connect the one panel I get about 33 W charge through the controller. When I connect the other panel I get about 28 W. Not amazing but ok. The problem is when I connect both panels in parallel I don't get much more power. I just get about 35 W. What am I doing wrong? Or what is not working as expected? Batteries are 12 V AGM batteries and was charged to about 12.7 V, so they should easily accept more than the 2.5 A the regulator produced.

MPPT SmartSolar
2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

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

2 Answers
Rob Fijn avatar image
Rob Fijn answered ·

Hello Magnus, mixing different panels is never a good idea. The result could be unexpected. And I guess that is what you experience now.

Do both panels have exactly the same specifications, you can compare the label at the back on the Solar Panel.

Regards, Rob



2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

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

magnus avatar image
magnus answered ·

The specs are not the same but pretty close. Pmax 40 W vs 50 W (I thought both were 50 W). Vmax 17.4 vs 17.6. Imax 2.31 vs 2.84.


2 comments
2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

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

spirou avatar image spirou commented ·

Vmax is too low to even turn on the regulator most of the time probably. Wire them in series and you might get more use out of them.

0 Likes 0 ·
ejrossouw avatar image ejrossouw commented ·

If you search youtube, you will find some great demonstrations of what happens when you mix panels. Connecting them in parallel is best, but it definitely will not give you the desired outcome.

0 Likes 0 ·