Solar Controller

[j_a_wolfe]

I'm not a beginner but hope to someday become one . . .
In any case, I have added equipment to my fifth wheel including 2 paralleled Lithium 12V batteries, Victron Inverter, DC to DC converter, and a Victron MPPT 100/50 solar controller.
In my excitement of putting things together, I purchased 4 solar panels at 200w per. Now I've determined that I have too much panel for the controller. Would I be smarter to upgrade the controller to a larger size or can I get another 100/50 and operate it in parallel to the existing one to charge the single battery bank?

Thanx,

Jim

 

[mikefitz]

Now I've determined that I have too much panel

Don't think so. 800 watts of panels, under ideal conditions via a MPPT controller, charging at 13.8 volts, could delivers 58 amps. In practice the panels will not deliver 800 watts, typically the maximum current will be In the 40 amp area.
Even if conditions were ideal and the panels generated 800 watts of power, the Victron controller will safely limit to 50 amps output.

 

[Brucey]

The four panels should be a good fit, and can definitely add a second controller in the future and sync them up via ve.direct and the Cerbo.

 

[wiseacre]

as already stated, 4 panels is fine and you could actually go to 6
the real limiting factor is VOC
I have 3 different 200w panels and their VOC's range from 22+V to 24+v
4 panels in series would likely be pushing the 100 VOC limit,
in cold weather I'd be afraid of exceeding the 100v limit with 4 panels in series and frying the controller

A 2s2p array would be fine
adding 2 more panels to make a 3s2p is also fine
as long as you don't go more than 2p no fusing the strings is necessary
although no fuses are necessary it would be nice to have a shutoff switch /circuit breaker to turn off the array if necessary

I had a 3s4p array (200w panels) wired into a combiner box running on a 100/50 - the SCC handled it fine although it ran a bit hot and occasionally had to clip some production. I was gifted a couple 300w panels and upgraded the old array to a 150/70 and used the 100/50 on the new 300s.