I have 5 panels, each is 40v, 345 watt. In series this is 200 volts.
I could wire them in parallel or series.
You most wouldn't recommend wiring them in parallel unless you have shading concerns on your roof.
You could put 4 panels with 2 parallel strings of 2. The the 5th panel on a separate charge controller.
If you put all 5 in parallel, you'd have 40+ amps coming out of the array, into the charge controller.
While a series string is simpler as you just have the 2 smaller gauge wires that need to penetrate the van wall.
I want to have a 12 volt system so I can also charge it via the alternator on cloudy days.
What is the right charge control or charge controller for this?
There's literally hundreds of options. Victron is a quality, reliable, top tier choice. Are you working with a tight budget? Does a $600 Victron make you want other options? If you provide your full panel specs and coldest temps you'll ever see, someone can do the math to see if you can get away with a smaller charge controller than the 250/100
Background:
17' Uhaul RV conversion. Going for off-grid as possible. 2" insulation all around. Mini-Split will be installed. I like it to run 24 hours a day if possible. I have 4 12v 100 ah lifepo batterires but can buy more. I will upgrade the alternator and use a proper dc-dc charging method. The panels fit
Depending on your ratio of parked to driving time, solar or alternator charging may provide more energy. But there's no free lunch, alternator charging burns more fuel (so does the wind drag from the solar panels)
Not asking him to put an array rather a 4 different systems (each panels) dedicated for 4 different batteries.
There's a pretty easy assumption that all 4 batteries will be paralleled into one battery bank. Not that each battery needs it's own solar panel and has it's own loads. That would be a weird setup on an RV.
He will not be stranded when one fails even if they are not actual MPPT.
If he is on a "budget" he should spend more on batteries instead of overpriced Victron otherwise it doesn't matter.
This isn't your budget, don't assume someone has your Top Ramen budget or sunshine_eggo's unhealthy obsession with Victron. I'm sure there are decent options between totally inferior PWM charge controllers that will hobble the array and likely require the Op to purchase spares from the slave labor in China and $600 charge controllers that will hobble the food budget for a month.
More details from the op would help narrow down a good recommendation.
