Bought for a mountain bike raid autonomy of several days (summer). The charging times given by the manufacturer are false. Much longer time. I never managed to fully charge the device, even leaving it in full dodger all day. It delivers very little energy it has stored, however. Shelved for 1 year for the following summer highlights: charging by solar does not work anymore, I have to recharge the battery from my PC via USB cable: hello utility. This is a gadget that is reflected in the quality of components, nothing stands in place. Avoid this, move towards serious kind: Goal Zero Nomad 7