Yeah, the f10v2 also has this problem, it just wastes power because ot can't be turned off, like yours. Mine I have to change batteries once a year because of that. A shame, because when you 1st get it it is turned off but once it is on there is no going back.If its anything like mine, it doesnt turn off, just goes into kind of a non use mode or a "screen saver" type of mode where it just shows like the time. Maybe look for the manual tho and see if theres a way?