I love this! It does exactly what it says on the box, allowing me to change my phone, kindle, and batteries for the lantern.
I was skeptical when I first bought this, basing my expectations on solar technology from ten years ago. Obviously technology has improved and the unit does actually change things relatively quickly. It does help to have direct sunlight but it still works on overcast days, just not as quickly.
I usually tie this to my tail bag and let it do its thing all day, then at night I change what needs charging.
Its a good idea to grab some spare batteries so you have spares.
Solar charging that works.
None so far.