The amperage rating of the Victron solar
controllers is for the charge current of the battery
, not the current from the solar panel.
When you get 10A at 37V from the panel, and we assume 100% controller efficiency and a 13V while charging
an empty 12V battery
, you get just under 30A. So yes, the 30A model is good because we put all the numbers for a theoretical worst case scenario.
This way you can do the math for any panel. If at all fitting your budget
, I recommend to get a 100/30 for each panel, instead of mixing with 100/20’s. It’s easier to have all the same plus it allows more options in the future
I would skip the Cerbo and display. Instead, get a BMV712-smart battery monitor
. I would also skip the BMS and either keep a multimeter at hand to check balance now and then, while using the BMV712 to check SOC, or... take a much simpler BMS DIY
style like I’m developing and document in another thread here in the Lithium forum.