Hey everyone! I've got a pair of 50W solar panels linked together, making a 100W setup, which I connected to a solar charge controller and a 48V LiPo battery. In bright July sunlight here in North Carolina, my charge controller shows an average input of about 0.40 amps. If I calculate voltage times amperage, that's only around 19 watts going into the battery. Is the 100W rating of the panel misleading, or is there something off with my setup? Appreciate any insights!
3 Answers
It sounds like the main issue is that your 100W solar panels usually need about 5V more than the battery's voltage to charge effectively. Most 100W panels produce around 18V, which isn't enough to charge a 48V battery properly. This is likely why you're seeing those slow charging rates. Keep in mind, they can recharge it, but it might take quite a while depending on how much sunlight you get!
Just a heads up, LiPo batteries are lithium polymer, which is different from LiFePO4 batteries. Make sure you're using the right charging equipment and settings for your specific battery type!
Yeah, that 100W rating can be a bit misleading. Typically, in good sunlight, those panels might only deliver around 50-60 watts. The bigger issue is that your setup may not be right if the output voltage is too low for standard 48V solar charge controllers. To get decent power, you should have a setup where your Vmpp is above your battery's voltage. It might be worth adding two more panels in series for better efficiency!
Appreciate the advice! I'm planning on getting another panel to add to my setup.
Just check the VMP of what you're getting; looks like mine is 18V, and my Eco-Worthy controller works with 48-72V.
Thanks for the clarification! That makes sense. I do see it recharge from 50% to 100%, but it takes about three days of good sun.