2007 Pontiac G6 - Key Fobs Battery Keeps Dying

One of my key fobs goes thru a new battery every week. Batteries purchased were brand new. Is this key fob repairable or should I have it replaced. I do have another key fob for the car that works properly.

was it ever exposed to water?
water (especially salty one) can contribute to quite fast drain.
if this is the case, I would disassemble it and wash in rubbing alcohol, then dry for a day or two before reassembly