iPhone 3G's battery dead!?!?

As I normally do to run my iPhone 3G's battery is dead every day, then load it night. This morning I woke up with my iPhone 3G still load the bar with warning lights and read a radius on the screen, nothing more. I tried to connect directly to my computer, but does not recognize it as a device. I turned off the iPhone 3G then again, that brought me back to the home screen. The battery level was 5%, but after fell to 1% and closed again! Any ideas? Edit: I forgot to mention that my warranty expired a couple of weeks ago.

have you tried another charger accident? If another charger does not work, I would take it right into the Apple store.

Cellboost