Phone dies on new full battery after few seconds
I just replaced the battery on my iphone 3g with a 1600mah version. Upon restarting, everything is fine, but the phone shuts off after only a few seconds of use, even when showing full battery. I have charged it for about 16 hours, it shows full charge but still shuts down after about 10 seconds of a phone call. It gives a short rotating white ring, then dies and cannot be restarted (does not show flashing battery logo). When I connect the adaptor, it restarts with white apple logo and is fine (although a couple of times it needed a reset of date and time). Each time it has restarted, it shows full battery.
It doesn't do this when connected to the power adaptor.
Everything else seems fine - docks ok.
Have I installed a dud battery, or does it need some kind of shock to wake it up?
Hope someone can help me.
Is this a good question?