Bests & Worsts Reviews from Amazon

In my original review, I complained that I was only getting about 5W from this panel, not the 20W that's advertised. It turned out that this was due to my using a long USB cable (8 foot). Now, if I switch to a short 2-foot cable, I do indeed see the "full" output: roughly 9W. It's still not 20W, because you can only get that by plugging in 2 devices at the same time -- you get ~10W per port for a total of 20W. So you can't actually charge one device at a rate of 20W. I'm changing my rating from 3 stars to 5 stars, because I do really like this panel, and it basically does what it says it'll do. Still, it is frustrating that you can't use a longer cable and get a full-power charge. I put the panel outside my window and run the cable into the house, which I obviously can't do with a short 2-foot cable. And it's also frustrating that you can't charge a device at 20W even though it's a 20W panel. Anyway. I've been using this panel on a daily basis for several months now, and I do recommend it -- at least until they release a 40W version, which should be able to deliver 20W through my long cable, I hope! One other nice feature: this panel is extremely water resistant. Mine's been outdoors in the snow and rain for about 9 months, and it's still working great.