I'm having trouble with a 20 watt solar panel trying to charge my 100Ah LiFePO4 battery that I use to power a bilge pump on my boat. The pump only draws around 1Ah per day, and while my 50 watt panel charges the battery just fine, the 20 watt panel doesn't seem to charge it at all. Any ideas on why this is happening?
3 Answers
It sounds like the problem could be related to your charge controller. The specs of the panels and what type you’re using can make a big difference. If the controller isn't suitable or isn't designed for lower wattages, it might not allow the 20W panel to charge at all.
Have you checked the output voltage of both panels? Sometimes, it can be the difference in voltage that affects charging. It's essential to know if the 20W panel is outputting enough to actually start charging your battery.
20 watts is generally on the lower end for charging a 100Ah battery, especially if you're using it for anything else like a bilge pump. Even on a bright day, considering losses and efficiency, you might find it underperforming compared to your 50W panel. If your charge controller needs a higher input voltage to function, that could also be part of the issue.
So, if the 20W isn't cutting it, should I upgrade to a bigger panel for better performance?
That's a good point! What type of controller are you using?