inputs.text: best used - give 4 stars cause almost battery backup could not ask better one charge two iphone4s fully left takes 4 hours charge usbthe solar part still ok full 13 hours direct sun got blinking 2nd light another 12 hours 621 longest day year full light blinking 3rd light keep devices powered ehemergency calls not full day usagelots others said got 2nd panel increase charge part hoping could keep without extra partthe main goal use backpacking taking full charge using power one cell phone could last 4 days really start using sparingly