I would hope it doesn't let you get to these true 100 and 0%'s too, it just that there is a lot of confusion over how *best* to treat these batteries. Personally I go up to the 100% and then after my day (on current 3gs) am usually down to about 20% I then go all the way back to 100% - however, my point is that if I can grab extra juice during the day, that is only a good thing, and you don't need to feel bad about not giving it a full charge