Laptop Battery Issues

So my dad just gave me a hand-me-down laptop. I get it home and it runs fine, so long as I use that AC adapter. The laptop in question is a recently reformatted HP Pavillion N5420. According to the power options and the light on the computer, the battery is 100% charged. But when I remove the AC adapter, *poof*, it shuts off like we've lost power, literally. Basically, the battery isn't functioning. What I don't understand is the power options recognize the battery and it's charge. Is it lying to me? lol

My brother is suggesting a lose wire within the computer, anyone else have any other suggestions? I mean, I'd like to be able to use the computer outside of the 2 foot radius from the wall plug.

Any help would be greatly appreciated!

The battery may be plain dead. Try with another. You don't have to buy one - just ask in your local friendly HP repair shop or whatever.

If it fails with a known good battery, then you have a fault in the battery/charging circuits. If you are good with electronics,you can try to find and repair the thing yourself, but it would be better to just let the professionals take care of it.

Always ask for a price estimate first - some jobs may be more expensive than getting a newer/better laptop.

Thanks for you response. I was thinking that myself, the more we got to messing with it. The battery itself it fairly new, but it's a generic brand that my dad bought. My dad said the same battery worked for him prior to the reformat, but it hasnt worked since. Ah, well.....off to the maytag repairman i go...