[batpot]

also, when you leave the phone plugged in, once the LED does from amber to green, it basically stops charging at that point, and if the phone is on, it will obviously keep draining the battery...I think once the led turns to green, it cycles charges to keep the battery above 90%.

You can demonstrate this by unplugging the phone a little while after the LED turns green, and then immediately plugging it back in, and see that the LED goes back to amber.