Update to my review: I've found you can't rely on the status light to indicate a full charge, but it does seem to work OK otherwise.The first time I used this, the indicator light went from red to green in less than 15 minutes. This should have indicated the battery was charged. The phone display agreed. I unplugged the phone. Half an hour later my low battery tone went off and the display showed low power. I rebooted the phone and the display showed full power. For subsequent uses I have learned not to rely on the indicator light.