I have had this unit (@4-1/2" diameter at mounting surface looks like). since 1995 so it does not owe me anything, but it was no longer spinning so, as a couple of times in the past, I put a fresh (rechargeable, as per spec.) battery in. Did not start to spin. I spun it a bit, it ran for maybe 10 seconds and then died. The +/- contacts look to be very clean an d free of corrosion. Anything I have missed, like pulling the impeller and lubing something? Anyone had this issue. This has been a good little unit so want to keep it going if I can.