I'm curious about charge controllers that have 'Load' terminals, like the Victron models. Do these terminals only provide power when solar panels are actively generating energy? Or can they also deliver power simply because they're connected to a battery, even when there's no sunlight? I'm looking for a setup where I can have devices running during the day without dealing with complications from reverse polarity photocell switches.
3 Answers
You're right, the load will generally draw from the battery. It's a good idea to have a small battery in there—it helps to handle quick drops in solar input, like when clouds pass by. Make sure to set a cutoff voltage so you know your battery won’t get too low after dark.
I've found that it can be a bit confusing since the documentation isn't great. From my experience, it's essentially a switch that allows small loads to run while connecting to the battery's voltage. You can have it in a mode where it operates based on the solar input, but it can also just stay powered all the time if that's how you set it up.
The 'load' output can actually work without the solar panels connected. I've used one before, and it was great for keeping the load from draining the battery too much. If solar is connected, it can also manage the load according to daylight—like turning on at sunrise and off at sunset. Pretty handy!