Best configuration for 4 x 175w panels

[Sean3007]

Hi, I have 4 x 175w panels to wire to my van through a Victron 100 | 50 MPPT controller. The controller could handle wiring them in series, parallel or 2 series pairs in parallel.

I was wondering which configuration people think would be best?

Originally I was going to go with series then changed my mind to 2 series pairs in parallel, one each side of the van and now I’m not sure.

I’ll be splitting my time between Portugal and the U.K. so imagine I’ll encounter quite a bit of shade at times.

Any advice very much welcome.

 

[Rednecktek]

What's the VoC of those panels? With a 100v hard limit (80-ish practical limit) I'd be really surprised if you could do a 4s without frying your controller.

Going 2s2p would give you the best mix of voltage overhead and lower-light charging. Plus, with only 2 strings there's still no need for a combiner box or fuses like you would need to go 4p.

 

[Sean3007]

Th

What's the VoC of those panels? With a 100v hard limit (80-ish practical limit) I'd be really surprised if you could do a 4s without frying your controller.

Going 2s2p would give you the best mix of voltage overhead and lower-light charging. Plus, with only 2 strings there's still no need for a combiner box or fuses like you would need to go 4p.

Thanks for the reply, it’s a 21.6v open circuit voltage but I’ll stick with the 2s2p, thanks again, have a good weekend.

 

[Rednecktek]

That low a VoC, a 4s series would be optimal if you can get it out there. It'll help generate power under lower light conditions.

 

[MattiFin]

That low a VoC, a 4s series would be optimal if you can get it out there. It'll help generate power under lower light conditions.

2S should be plenty even in low light.
Note that optimum voltage for solar panel stays fairly constant irregardless of light conditions.
Panel that is rated for 200W and 20V 10A operated in low-light conditions has maximum power point at somewhere like 18V and 1A.
In some cases when low radiation results in cold weather and cold panel it is even likely that low-light MPP voltage is higher than it would be in bright sunshine.

https://www.researchgate.net/figure/P-V-characteristics-at-various-temperature-and-solar-irradiance_fig2_309600416

Effect can be seen also forexample here: https://pdf.archiexpo.com/pdf/jinko-solar/standard-module-jkm210m-72-190w-210w/68245-144664-_2.html