Solar Panel Connectors
I am a complete newb with solar panels. I just bought a camper that has an older 50 watt solar panel and 20 amp charge controller. The controller itself looks to be a quality unit and I think I will k...
Forum Discussion
IMO you can use the "20a" controller for the 50w plus two 100s.
A solar panel can at times crank out more amps than it is rated for, which rating is done at standard test conditions including 25C temp. The usual recommendation for controller amps rating and fusing of the pos wire from controller to battery is to have a 20% margin.
A "20amp" controller is designed to run at 20 amps without overheating. To have a 20% margin, the panel should be rated at no more than (1/5 more needed so 20 is 6 parts = 3.33a a part ) 16.67a
You use the rated Isc for normal expected max amps. A 100w panel should be 6.3a approx. Your 50 might be half that 3.1 say. So two 100w plus your 50 could get you 12.6 plus 3.1 = 15.7a which is under 16.67a
A solar panel can at times crank out more amps than it is rated for, which rating is done at standard test conditions including 25C temp. The usual recommendation for controller amps rating and fusing of the pos wire from controller to battery is to have a 20% margin.
A "20amp" controller is designed to run at 20 amps without overheating. To have a 20% margin, the panel should be rated at no more than (1/5 more needed so 20 is 6 parts = 3.33a a part ) 16.67a
You use the rated Isc for normal expected max amps. A 100w panel should be 6.3a approx. Your 50 might be half that 3.1 say. So two 100w plus your 50 could get you 12.6 plus 3.1 = 15.7a which is under 16.67a
