My new 15" had the same issue. Try another battery, hopefully that fixes it, in that case it was a faulty battery. However, if yours is experiencing the same problem as mine did, the new battery will not make a difference. It will need to be repaired/replaced by Apple.
Mine was 4 days old when I took it to the Apple Store, and since it was a Custom-Order I was not able to get a replacement at the store. So I had to call AppleCare and have a return order processed. Takes about a week. And you get a brand spanking new machine.
Hopefully Apple treats you as well as they treated me. They declared my machine DOA (Dead on Arrival) and after that point they really took care of me.
Good luck!