Interesting that you're experiencing poor battery life with the D5500.
I was just remarking to my dad that the D5500 appears to have remarkable battery stamina
Got it as a 2nd (or make that 3rd) camera, intending to use it for snap shots and video.
Recently brought it along to my regular badminton game, recording almost an hour's worth of footage (with the screen on throughout).
The next day I brought it along to a social cycling event to take some candids and group photos, maybe about 30-40 shots. When I returned home, the visual battery indicator still showed it was full! Obviously it wasn't at 100%, but that was still pretty remarkable.