I just replaced my four year old Propointer with a new Propointer 11 and something seems amiss. The battery that came with the new pinpointer lasted about thirty turn ons before the low battery beep started. I replaced it with a new battery and the new battery ran out of juice after about 60 turn ons. I also thought that it was not as sensitive as the old one and the speaker was weaker. I was under the impression that it had slightly more sensitivity than the original. For the record, a battery would last two to three months of hard detecting with hundreds of cycles of the button. Hopefully the newer pinpointer does not use more battery power than the original.