There isn’t enough sun light in my area to fully utilize the full capability of the 2 usb ports. At best, 10w on certain time of the day, but it remain around 5w most of the time.
Hi Kevin, welcome to the community.
The current 21W solar panel makes up to around 15W in good conditions, and at 5V 2A 10W limit of one port, a 2nd port helps to soak up any excess, plus you can charge two things at once, like a Powercore + flashlight.
It’s trade-off to go larger, more weight bulk Vs more useful energy.
If your conditions are such you are only getting 5W then is solar the right solution?
I’ve dabbled with solar for > 20 years, and Powercore have become sufficiently good, having a week’s energy and recharge in a few hours, I ended up just doing that and buying two 10Ah Powercore and a dual socket Powerport and make use of wall sockets when I encountered them. Proved most reliable in real life.0
I own 3 solar panels, they tend to not get used as when packing them, feeling their size and weight Vs a Powercore and sun is not that consistent reliable.
I keep a couple of them in the closet as backup (our community power company doesn’t maintain the lines very well, to many trees to keep cut back) so I tend to keep my larger power banks full and use the smaller power banks with solar charging. During the summer I get decent charge time and but I plan that it could take all day to charge a large power bank. My solar panels are about 3 years old and from another brand and they get close to the 15 w I think. I still need to pick up a tester and do a true test.
I agree with @professor you might want to look for another solution if you are getting only 5 w.