Does boot take up any significant power? If I wanted to conserve energy, and needed to check on my phone once every while, would turning the phone off and on every 30 seconds actually conserve more power than if I had it on all the time?

Does the boot sequence perhaps take more energy than the energy I saved in the off time, thus having negative "profit" of power save?



My phone is running CyanogenMod 12.1, and is a kminilte (S5 mini)
Yes, booting the device is very expensive in terms of power consumption.

Many reads from the storage and lots of computation needs to be done when booting the device so that you need considerable off time to justify turning it off.

Android's power conservation features (deep sleep, dozing etc) allow you to keep your phone turned on all the time and still consume less energy than booting it freshly.