Series or parallel RV with Victron MPPT?

[Isaac-1]

I am upgrading the Solar setup on the roof of my 28 ft motorhome, this is a 12V system with 420AH LiFePo4. Current installation has 4 100W Grape Solar panels in parallel installed by the previous owner 10 years ago, (I upgraded from the PWM to a Renogy 50 Amp DC-DC charger with MPPT solar in 2022 with the LiFePo4 upgrade). I am going to be utilizing components I have on hand, left over from other projects, etc. primarily this includes some post hurricane salvage LG Neon 305W panels, and a Victron 100/50 MPPT (the LG panels 40V VOC, 10 amp ISC so no more than 2 in series)

My plan is to keep the current 4x100W panels and Renogy DC-DC MPPT, and add 2 of the LG Neon 305W panels for a total of 1010W using the Victron 100/50

The quesiton is should I wire the LG panels in series or parallel?, note due to placement of the existing panels, vents, sky light, etc. the 2 LG panels will be around 15 feet apart and mounted perpandicular to each other in an L shape. I only mention this as it probably increases the chance that one will be shaded. (spec sheet for the LG panels says they have 3 bypass diodes).

thanks for your thoughts

 

[pollenface]

I'd go parallel for possible shading issues.

 

[HRTKD]

My experience with my RV is that if one panel is shaded, the others probably are also shaded.

I have four 420 watt panels configured 2s and 2s into two 150/35 solar charge controllers. When I get around to adding a couple more panels the existing panels will change to 2s2p.

I would run your new panels as 2s. If you find that shading causes problems, you can always change that to 2p.

 

[justinm001]

My experience with my RV is that if one panel is shaded, the others probably are also shaded.

I have four 420 watt panels configured 2s and 2s into two 150/35 solar charge controllers. When I get around to adding a couple more panels the existing panels will change to 2s2p.

I would run your new panels as 2s. If you find that shading causes problems, you can always change that to 2p.

When under a big tree you're typically only covering 1 panel or so. Lots of places we can't pick where we park so can move up/down a couple feet but not much more. Its rare a tree, lightpost or building will cover the entire set of panels.

 

[Aussieguy]

my panels directly behind the air conditioner I expect some partial shading each day
I put them in parallel on a 100/50 as the 37v OCV were high enough to allow me to use the 10g factory install