I have left this solar charger on my window sill for a couple of weeks to fully charge and then took it out when i went out to watch a softball game and charge my phone during the middle of the game while getting more sun at the game too

The charger charged up my android phone pretty well my biggest complaint would be the rubber piece that covers the usb is a bit flimsy and the carabiner is very cheap but overall what could be better than getting a free charge from the sun we thought initially that one of those portable solar panels would work but then realized those panels have no builtin backup power storage so would only be able to charge the phone whena the phone is attached to itb when the sun is shining brightlyc the panel is aimed toward the sungiven their trip is southbound we realized the panel would not be facing the sun during the day when shes hiking unless she wears it on her chest instead of the pack not good

But the battery recharges our phones very quickly and if she charges it up fully from a wall plug at the motel prior to the trip should last the week keeping the phone fully charged

I am writing this review in exchange for a discount