It took me a couple of minute to turn on the ACU in my bedroom. The remote control's two AA battery has run their course, so to speak. I had to take out the batteries, blow, shake and beg at them (for a last hurrah) before putting them back again in the remote control. It worked! I have AAA rechargeable batteries, remnants of my son'd remote control car days. I think I need to get a best selection of powerex AA batteries for the house. Just a few minutes ago, Ethan was also in need of one AA battery for his alarm clock and I have nothing to give him.