Reason for rating: Works, but with a catch.
The panel charges unsteadily. It doesn’t deliver a steady charge, unless you leave it stationary under direct sunlight.
I planned to use this when I go hiking or backpacking, by throwing it on the back of my pack to get some juice while on the go, but I doesn’t seem like this panel will be ideal for that use.
I tested the panel by putting it under the rear window in my four-door Camry sedan on a sunny day, when it would almost constantly be in the sun. I drove my regular commute to work, while my phone was plugged into the panel (instead of the cig lighter charger I usually use).
When I was driving under direct sunlight, my phone would charge beautifully. However, if I went into shade, even for a moment (like driving under a tree or past a building), my phone would stop charging and start again once I passed the tree/building/obstruction. During my whole commute, my phone kept disconnecting and reconnecting every time I passed any sort of obstruction that blocked direct sunlight.
By the end of my commute, my phone actually had less battery than before, because the screen would turn on and the phone would play a sound effect every time it started or stopped charging.
I’m usually a fan of Anker products, but this issue with the panel is going to be a big problem for me. It makes it almost unusable for my intended use, because if I even turn around to face the sun for a moment with the panel on my back, my phone/battery pack/tablet is going to stop charging and restart when I turn around.
It shouldn’t be difficult for Anker to build in functionality to ensure that the panel charges steadily, even when taken out of direct sunlight briefly.
I later tested the panel again by leaving it stationary under direct sunlight, and it worked great then. It charged my phone faster than I would have expected, but the problem with getting a steady charge when hiking/backpacking/going mobile is going to be a pain for me.