I'm experiencing a major issue with my solar setup. I get a solid voltage reading from my 24V solar panel wires, but as soon as I connect them to the charge controller, the voltage drops to below 5V. This system was functioning perfectly for the last couple of months since I upgraded the wiring from the panels to the controller. I've checked all the junction boxes along the way and the connections are fine up to the charge controller. The controller still seems to work okay, and I even swapped in a spare controller, but I'm still facing the same problem. I could really use some help because I rely on this off-grid system!
2 Answers
Since you have good voltage when disconnected but it drops when connected, it seems like you might have a bad connection somewhere. When you connect the circuit, the poor connection can cause a significant voltage drop. Try disconnecting the PV wires from the charge controller and shorting them (this is usually safe for PV circuits), then measure the current with a clamp-style multimeter. If the current is lower than expected based on current sunlight, the issue is likely with the wiring.
What's your entire setup look like? If you just replaced the wires, double-check the polarities. If you're using MC4 connectors, make sure they're hooked up correctly—positive should be female and negative should be male coming from the panels.