Originally Posted by Lunchtray
I'll need to test that out but I highly doubt that only running standby will increase battery life due to the 24hrs/day standby drain and reading vs powering up a few times a day and reading.
There's probably a limit where powering it up from off will tip the balances in favor of sleep but it's probably a large number of boots.
One thing to try in your tests is to keep the Kobo in sleep when you finish reading on the train until you finish reading in bed. The time there is too short to get an advantage out of a full shutdown/reboot.