Just wandering if using Two 9 volt batteries in the Tejon would hurt it in anyway. Bought a used Tejon that had been sitting in a Garage for 2 years with the batteries left in it. I cleaned it up the best i could, using baking soda to counter act the acid from batteries leaking and put a new set of batteries in it. It just doesn't seem to be working correctly. I was thinking of just getting rid of the double A packs and putting a 9 volt battery in each side if it won't hurt the detector. I hate to send it in to be repaired for the batteries being left in it if i can do a quick fix myself.