We already had one of these:
Posts there were mostly about fresh FP2 batteries though.
My 3 years old battery needs about 40% a day for normal usage. Though normal usage is rare even though I don’t use any of the usual suspects (FB & Co).
When I’m at home I usually have my phone plugged in most of the time while Battery Charge Limit (topic) makes sure it stays between 80% and 70% and BOINC (topic) makes sure it drains from 80% to 70% fast.
When I’m commuting I usually have GPS, Wifi & mobile data active to gather data with Mozilla Stumbler and OpenWLANMap (wiki) and have the screen on to browse the fairphone and other forums or play a little game. That probably drains about 10% in an hour.
When I’m hiking, biking or walking my dog I do the same without the constantly on display. This way the battery badly needs a charge in the evening, but usually I make it thorough the day still.