Currently Being ModeratedAug 11, 2012 12:15 PM (in response to joey78)
It could be a defective battery however, Apple will require you troubleshoot in order to rule out any software issues first.
you will need to restart the device and deplete battery til it powers off; then once charged to 100%, test how long it takes to fully drain to 0% again.
tech specs on iPhone 3GS below:
Currently Being ModeratedAug 12, 2012 1:05 AM (in response to esilva208)
I charged it fully last night at 1900, unplugged from charger and left it on satndby, i've just checked it and it's on 10% its now 0900 the next morning. All Apps closed however i dont really have any apart from those that came with the phone, as I said ive only just started using it.