i have an old laptop which has a bad AC power supply (it cuts out at random and i have to replug it). As i never move the laptop, what i have been doing is using AC power and when the power cuts out I have been using the battery to 'support' the laptop until i have replugged the power pack. Now, all of a sudden, the battery isn't working. The laptop thinks it is at 100%, but it probably isn't because when the power cuts out the machine goes off. So what could cause this? I would be surprised if it was just a dead battery because a few weeks ago i could use the battery for over 30 minutes no problem. Could it be a bad connection in the computer, or is it a setting problem? A friend said i should try to reset the battery, but i have no idea how to do this, is it easy?

Hi dave: You should be able to buy a replacement AC adapter (look at Radio Shack), just make sure you have the correct voltage, amps, & correct polarity plug (the positive & negative to device). As for battery, it's probably a Ni-Cad which means you need to run battery down to recharge properly (if you don't run down, the battery memory gets less with each recharge until the battery won't hold a charge). Some newer batteries don't have the memory problem, you can recharge anytime. Good luck. Z

Is this a Dell?