Potentially serious problem with the battery/AC adapter (XPS M1530, 1.5 years old)

Hi, my notebook is a XPS M1530, nearly 1,5 years old.

Thanks to my geeky-carefulness, nothing ever broke and it "fell" on the side (from standing position to flat one) only 3 times while being inside the "armored" bag. I never had a strong crash like a Blue Screen Of Death. I could sell it as "brand new" no one could see it's 1,5 years old.

Yesterday, while it was recharging the battery (a 9 cell one), the A/C adaptater start beeping rapidly like if it was an emergency signal, the green LED was blinking, so I rushed and unplugged everything.

After making a fresh backup of all my important files on the battery mode, I tried to launch the notebook again, but when I plugged the a/c adapter it says "plugged in, not charging" (nb : I translated it in english). Moving the jack connector didn't help. Suddenly, it crashed with a quick bsod.

Then, I experienced the same "working 1 minute then BSOD" error 5 times in a row, everytime I tried to plug the ac adapter.

Using only the ac adapter without the battery allowed me to finish quickly some very important work (I'm a student) planned for tomorrow.

Then it gets strange again : after hitting the ac adapter a little on the ground (to see if a simple hit could provoke that bosd/beeping sound), everything went back to "normal" : the adapter was working correctly, the battery was charging, and the notebook was no longer crashing.

So I decide to recharge my battery while I was there to watch over it (don't want to set my appartment on fire thanks to exploding batteries), there was no problem.

I used my notebook on battery mode today for 6 hours without a single problem. I'm writing this message with that notebook right now.

I know batteries and ac adapter have a limited lifetime like any components, but I was wondering :

- should I buy a new Dell adapter ? there's a lot of negative comments on them, lasting only 6 months to 1 year. nb : These adapter may NOT be the same we get when buying a new Dell.

- sould I buy a new Dell battery ? it's the same, I read a lot of negative comments about it.

- should I unmount my notebook to check the power part (the jack connection part) ? I don't think that part is broken, but if it's a common problem I'll do it.

Thanks for your help :)