Before spending money on a new battery, try charging it for at least an hour on household mains power (i.e. not through the car charger). The car charger will not recharge a fully flat battery.
Then do a factory reset on it - press a pin onto the reset button in the back for 10 seconds then switch back on. It should come right up. Exact same thing happened with outs.
Noel
September 2008