I'm pretty sure you mean 1.5v (not 5.5v) for the Energizers.

EDIT: As it turns out (and which I forgot to mention) the NiMHs tested out at 1.5v just prior to being put into the mouse.
And a spare set charged and sitting in a drawer still test at 1.5v.

What's even more interesting ... When I put the NiMHs into the mouse straight from the charger, they registered 88% on the battery level meter. After several hours' use they now register 100%. Go figure.

Last edited by grelber; 10/27/11 01:50 PM.