360 wireless controller not "keeping sync"?

Thats kinda hazy title.

I have the official Ms wireless 360 pad since 2007. IT has worked fine for 2 years, however , in the last month, it wont sync /or be recognized by the console.

I have tried new batteries. I have tried holding the little button on the pad and the button on the console to make the “lights” spin around, but it will take like a long ass time to sync and when it does , it loses sync/ shuts off after 10-30 seconds.

I havent altered damaged the console or pad. The only thing is since I live away from home for school, I have unplugged the console and removed the batteries for 3-4 months at a time from the controller. I dont know if that is significant but i thought id throw it in there.

Since this happened, i have been using a 3rd party gamestop wired controller to play; i dont know if that would affect anythign either.

Thanks for any help