With Gingerbread, there used to be a setting you could access so that you could tell the phone to sleep during certain times of the day if the phone was not in use. This caused my phone to actually only drop abut 10% or less in battery strength over night. With ICS I cannot find this feature, and since the update to the newest build, my battery has started draining 30%+ overnight again, with the majority of power being used by "cell standby" and "phone idle".
at least one good thing recently happened, in that my google maps now actually shuts down. When I would check battry usage before, maps was ALWAYS using about 20% even if I would force close and not use it for days.