After an initial charge via the USB cable provided, this radio has not needed a charge since apart from the sunlight charging it gets on the kitchen window sill. The design of the unit is good, and, while it feels light to hold, it doesn't feel particularly shoddy.
I have one slight gripe about the speaker. The volume is sufficient for most things, but near the top end of the volume scale, the speaker can distort, especially on some of the deeper voices on Radio 4.
However, that is a small gripe, and overall, it works perfectly for what I wanted it for, and feeling green for using the unit is a bonus! Nice bit of kit; I'm happy with it.