Input voltage for solar controllers series or parallel

[Glw]

Hi all.
Would love some advice as Im just getting started.
I am currently running a small solar system on my caravan that I have made some minor adjustments to but wanting to upgrade it. Currently I have.

1x250w panel feeding into epever 20a controller feeding into the combined 280ah agm 12v battery bank
2x100w panels in parallel feeding into epever 20a controller feeding into the combined 280ah agm 12v battery bank.

I was hoping of replacing the panels and upgrading to...

2x350w panels in series into ??(not sure on controller) into the 12v battery bank
2x350w panels in series into ??(not sure on controller) into the 12v battery bank

really looking for some advice to keep the cost and cabling to a minimum.


I was looking at combining into one

Victron SmartSolar 100/50 MPPT Solar Charge Controller - InBuilt Bluetooth​

or can I keep the pwm epever controllers if I run the 350w panels in series? They say they rate the controller at 50v input.

thanks everyone in advance for your help.

 

[snoobler]

Welcome to the forum.

280Ah battery bank needs about 28-42A (10-15%) of charging to be healthy unless the battery gives different limits.

42A * 12V = 504W

Some AGM batteries allow 20%, which would permit 56A

56A * 12V = 672W

It's okay to break the above limits by a little bit because of the nature of solar charging... they start slow and don't hit their peak until noon. On a flat roof, they may never hit peak. Check your battery spec for the recommended charge currents.

The 100/50 is an excellent choice and would work for up to 700W but the Voc of your two panels in series must be less than about 80V to allow for cold weather voltage spikes. If they are higher Voc, they may pop the controller, and you would need to upgrade to a 150/50. One nice thing about the victron is you can program them to deliver a max current if you want to limit your battery charging.

You can hook up multiple SCC, each with their own array, to the same battery bank, but you should not exceed the maximum charging current.

Again, it's often okay to have more solar than you might need for your battery. Once the battery is charged, the panels can be used for direct power consumption while they only float the batteries. You just need to be aware of and manage your peak charge current.

 

[Glw]

Thanks for getting back to me and all your great information.
so.... I’m hearing that my system will need to be thought out from the batteries. The batteries will take 30A initial charging current. Does that mean that I can put a maximum system of 360w solar array? give or take due to the panels being flat on the caravan. So my current system is already at max. Not worth putting any more panels on the roof?

Does the fact that I have two batteries change the 30A Initial charge?

can you make a suggestion to maximize my current batteries, I have attached the product spec.

I have also attached the panels I have been looking at

 

[Glw]

Sorry Attached the panels I have been considering.