Aspire D255 battery not working

Over night my netbook has stopped running of the battery. When plugged in to the mains, windows is showing that the battery is 100% charged, but as soon as i pull the mains power the netbook dies.
Now if the OS was reporting the battery flat or U/S then I would accept that the battery needs replacing, but this is not the case.
Any one have any ideas?

 

There was a trick for the older AAO's that may still work.
* Shut down the laptop
* Unplug the mains and remove the battery
* Hold the power button in for 2 minute
* Let the power button go, reinsert the battery and reboot the laptop

This supposedly resets a counter in the netbook. I've never had any sucess with it though. An alternative to get a better perspective on your batterys lifetim, is to download and install a program called Battery Bar from here. I've come to rely on it much more than the Windows power system, it provides much more detail about your battery. If your battery is dead (even if Windows isn't saying so) BatteryBar more than likely will let you know.

 

Many thanks for the reply.
I have already tried the approach of the 'reset' but to no avail. Once I get an opportunity to download the battery meter app, I will give that a go. This will not be until the weekend though when I get open internet access.
In the mean time, I will look for a replacement battery, just in case the current one is dust.