I've got two 100W solar panels, each rated at 5 amps, hooked up in parallel. However, my charge controller shows that in full sunlight, they're only generating 13V and 5.5 amps. Shouldn't I be seeing numbers closer to 18V and 10 amps? I'm using 10 gauge wire and just trying to charge a 12V battery for some small electronics. Could my panels be defective? Thanks for any insights!
3 Answers
Just a heads up, you've wired them in parallel, not series. That could affect the voltage readings you're getting. Also, make sure to double-check what your charge controller is reporting. It might just be showing what it’s drawing in, rather than the max your panels are capable of producing.
Curious about what brand or model your panels are. I bought a 100W panel on eBay that ended up being about 33% less powerful than I expected, producing only around 60W max. Luckily, I managed to get a refund by showing proof of the discrepancy. Make sure your setup includes an MPPT charge controller; without it, you’re likely to see lower voltage than expected.
It sounds like your charge controller might be the issue. If it's a PWM type, it can drop the voltage down to battery levels without boosting the current, which could explain the lower output you’re seeing. Are the panels positioned well for sunlight? Also, 5.5A does seem low for two 5A panels in parallel. Maybe consider checking that angle and controller type first!
Yeah, PWM controllers can be limiting. Ideally, you'd want to check if an MPPT setup might suit you better—it could help maintain higher voltages and increase the efficiency.