Solar Charge Controllers

[mustangbob]

I've been considering a Victron Smart Solar 100/50 charge controller for hopefully a 400 watt/300ah battery system. I have a wanting to sell me a Victron 150/35 controller instead. Any comments on either controller.

 

[snoobler]

Welcome to the forum.

The 150/35 will permit higher series PV voltage. If you're charging a 48V bank, this might be prudent.

Assuming 12V system:

400W/12V = 33.3A, so either should work.

If you plan to add additional capacity, like a deployable ground array, the 100/50 would offer greater capacity.

 

[willo]

Victron gear is solid. If you want the remote control on/off feature (for say a BMS) you end up going a bit higher end. Same for the relay output feature.
You can always run multiple controllers (from separate arrays) for more power.

For sizing, the key thing is to not exceed either max input voltage or amperage. The Victrons deliver a maximum wattage based on their max amp output - for mine it’s like 1300w at 24v but 2600w at 48v! So the higher your battery bank, the higher the max wattage. I’m running 24v on mine. To me it’s a good compromise of smaller wiring, but with a more performant system.

I would consider higher voltage if you are going to want a big inverter, more than 800w of solar or have a need for more than say, 2-4kwh of battery.