wireless controller disconnecting often

[Chomma]

Hello, I have a bit of a problem with my wireless controller. While playing COD4, in multiplayer or singleplayer, my wireless controller will start strobing in the middle jewel, and then turns off a few moments later when I do not expect it. I have tried new batteries, and I"m pretty damn sure batteries do not run out within two weeks, and I don't play every day. I play for about 2-3 hours a weekend, on average, and I either play too much, or my controller has a problem.

I am 10-20 feet away from my Xbox, or at least closer to my 360 than my friends whose Xbox 360 seems like 30 feet away, and they never have those problems. I am considering getting a rechargeable battery pack, and docking station, but I want to know if there could be a defect in mine.

Thanks.