Rare problem with the battery

Hi mates,

I've a rare problem with my battery.

If I charge the AA1 while it's running, whent the charge finishes , I get 2:30 hours from the battery indicator.

But as soon as I reboot, when It finishes loading, the battery indicator shows 1:50 hours left (aprox.)

If I charge it with the AA1 turned off, when I turn it on, I also get 1:50 hours left.

What should I do?

 

As an explanation I have heard that the battery calibration is not working properly. I believe the time remaining of the battery is measured by the drop in voltage. Fully charge and then let the computer run until the battery is depleted. Then recharge again. Repeat this a couple of times. This "teaches" the software keeping control of the battery life what full and empty is.