Well it's not really a surprise when you keep switching controllers (and thus batteries). The situation would probably look quite different if you used only one. I always have a primary controller (on 360 the one with the faceplate and on X1 the revised controller that came with the X).
I game about 30-40 hours a week on a regular week. And have been using these controllers for all this time without swapping batteries and almost ever 0 to 100 charges. The battery life is still enough for probably 6h or more straight play and since I keep one charging/charged while the other is in use I have 0 downtime. When it happens that co-op is needed and one drained out or my son took the control to use on the other PS4 I just plug on the outlet 1ft to my side and being wired becomes a 0 issue for me.
I have a day One controller for PS4 still works like a charm and i never had problems thinking about the duration of battery, and its always 100 to 0 and recharge while playing, same for 2 PS3 controllers.