Anyone had any problem with Dell Laptops Power adaptors? We've had a one for less than 2 months, and the Power adaptor isn't recharging the battery. It OK to use on the mains, but even that may be starting to be a problem, with the battery only on 3% power, and the laptop not working as well as it should.

Go into the bios and look for the battery section, a lot of dells have a utility in the bios for doing a drain and recharge on the battery

That sounds like the battery. I've got a similar problem with my Dell, but mine's nearly two years old, though I've had the problem for about 6 months. It's not really been much of a problem because I always used it with mains power anyway. I actually wondered if it was because of this that the problem occurred i.e. I never let the battery discharge which generally I believe you should to maximise the battery life.
I have, because I always use it with the power adapter managed to this week burn out my second adapter. Got the first replaced under warranty. But I won't be able to get the second one replaced. Fortunately I have a spare which I'm now using.
I would suggest in your case as your Laptop is two months old whatever the problem is you'll be covered by your warranty, so just contact Dell to get it sorted.