What type of batteries are you using? I found out from experience, the cheaper batteries like Rayovac, will only last a few hours. if you are using better quality batteries such as Duracel or Energizer, then it must be the keyboard and mouse itself. then i would take it back to Best Buy and exchange it. Also look at different type of batteries, i was told that regular one's will not last as long in some equipment such as AA2 which or those type. check with one of the reps as they are honest and are not working on commission. I hope this helps. Good luck