Originally Posted by Steve B.

Sorry, typo, meant AA. My 30 year old E-Trek uses AA,, yet when mounted on a bike (they made a holder) the vibrations made the batteries lose contact and the unit would not stay powered. I stopped using for cycling and got an 810, which was a very unreliable unit. Then the 1000 and 1030 and a 1040 and a 1050. Gadgets are addicting to me.