Solar panels on Van or RV Series vs Parallel (Real Life)

[charlie22824]

Hey I'm asking this again to see if I could get real life information and numbers from people.

I am curious on the communities opinion on solar panels Series or Parallel for Van Life or RV. I wanted to get a more in depth answer to people who actually use these two options in the real world on a RV or Van.

I have two Renogy 12v 200W solar panels currently in parallel with about a 17 foot span from the solar panels to the charge controller. I'm using 8awg to try and control the voltage drop.

I was thinking of putting them in series because I wanted to possibly add another solar panel later but, the panels would be pushing almost 30 amps if used in parallel. I'm going to be using a Victron SmartSolar MPPT 100/30 charging two 12v 400ah EG4-LifePower4 batteries in parallel.

Is it safe to put the solar panels in series with the VOC combined at 54volts to the MPPT charge controller to charge the Parallel 12v Batteries?

thanks for the help!

https://battlebornbatteries.com/product/victron-smartsolar-mppt-100-30/​

 

[Rocketman]

I answered this post as if you already had three panels- oops - the info is still the same.

Yes with your charge controller Victron mppt 100/30 it is perfectly fine.

In fact one of my arrays is just like…
Three 200w panels wired in series to that mppt.

That mppt can handle 100v. The Voc of your three panels are 27v times 3 = 81v. You have plenty of room if your panels are cold. In the future do not add a fourth panel in series. You will ruin the mppt. If you ever do add a fourth panel go 2s2p. You would probably want a bigger mppt too then.

We are both over paneled on the arrays. The max amps that mppt can produce is 30a which is about 420w anything above that gets clipped, but we will still have the advantage of more panels when things are not perfect. (Flat panels are perfect at noon in June).

If you haven’t bought the wire 10ga would be fine. 10ga will handle 30a. Because you are wired in series you only have 8.85a. Even three in parallel would work.

Good Luck with your project

PS - thanks for including all the needed info in your post!

 

[charlie22824]

I answered this post as if you already had three panels- oops - the info is still the same.

Yes with your charge controller Victron mppt 100/30 it is perfectly fine.

In fact one of my arrays is just like…
Three 200w panels wired in series to that mppt.

That mppt can handle 100v. The Voc of your three panels are 27v times 3 = 81v. You have plenty of room if your panels are cold. In the future do not add a fourth panel in series. You will ruin the mppt. If you ever do add a fourth panel go 2s2p. You would probably want a bigger mppt too then.

We are both over paneled on the arrays. The max amps that mppt can produce is 30a which is about 420w anything above that gets clipped, but we will still have the advantage of more panels when things are not perfect. (Flat panels are perfect at noon in June).

If you haven’t bought the wire 10ga would be fine. 10ga will handle 30a. Because you are wired in series you only have 8.85a. Even three in parallel would work.

Good Luck with your project

PS - thanks for including all the needed info in your post!

thank you for answering this again I just wanted to make sure 100% with a better update on my system.

 

[chrisski]

I wanted to possibly add another solar panel later but, the panels would be pushing almost 30 amps if used in parallel. I'm going to be using a Victron SmartSolar MPPT 100/30 charging two 12v 400ah EG4-LifePower4 batteries in parallel.

If you are adding to 30 amp total consider the 100/50 by Victron.

Is it safe to put the solar panels in series with the VOC combined at 54volts to the MPPT charge controller to charge the Parallel 12v Batteries?

Yes. I have a 100/30 and 100/50 and when I was 12 volts, I was at 60 volts.

Hey I'm asking this again to see if I could get real life information and numbers from people.

This is a balance of voltage loss from high amps and shading loss from panels. Here is how shading effected my 2p system and 3p.

Parallel Panels and Shading versus Series Parallel

I tested some panels for output today when shaded. 2 Panels in Parallel (36 Cells Per Panel) -One panels with only 2 cells shaded 26% Reduction in Wattage -One Panel 50% shaded 54% Reduction in Wattage 3 Panels in Series (33 Cells Per Panel) -One panel Two cells Shaded 33%-50% Reduction in...

diysolarforum.com

In general I believe in as much in parallel for a van in a Rv build as possible. Voltage loss should be no more than 3% to 10% with panels in parallel. To me, that came to 6 x 100 watts set up 3s2p and 6 x 175 watts set up 2s 3p.

Shading on mobile builds kills production whether it’s from a air conditioner or trees.