The thing should be under warranty if it's new, take it back and get it looked at. There are so many things that could be wrong that would cause that it's hard to even give any suggestions.
The contacts could be bad/bent/broken, the point the contacts on the inside of the laptop are soldered onto the board could be broken. The battery itself could be not getting a charge and thus be dead (this is different from an expired battery, if it has absolutely no charge the laptop won't pick it up at all but if it's just worn out it will always have a tiny bit).
The small circuit that handles power management inside the laptop could have failed as well, either it's not directing power to the battery or it's not receiving power from the battery or both, I've seen that happen a couple times with certain models. The chassis could be damaged in a way that the battery is not actually making contact do to sitting loosely inside its compartment.
If you were to bring it to me in person I could probably tell you in a couple hours what's wrong with it (this is the main thing I do for a living), but over an internet forum with a vague description I'm sorry it's really hard to say, and somehow I doubt you live near me. So take it to a professional in your area, especially if it's covered by warranty
