I think it has just as much to do with W10M as it does any hardware, just like it's desktop counterpart, W10M behaves differently even on the same device. On my 1020 It took 3 hard resets on .11 before I stopped getting crazy battery drain, on the second hard reset I turned off everything like location, Cortana, all background apps, sync etc. and still would be dead after 6 hours. After third hard reset with everything on I get an easy 24 hours. It's not an app issue either as I installed all the same apps every time. I installed .29 and no change in battery use, which is good as I didn't feel like doing another hard reset.