one outstanding feature of Android 6 is the "battery saver" mode. you may have noticed it come on automatically at 15%, but I wanted it on all the time, since I don't have phone service and just want it to last as long as it can between recharges.
it turns out it's a little hidden; you need to go to Settings | Battery and click the "context menu", those 3 vertical dots in the upper right corner. select "Battery saver" and flip it to "on". note that you can't do it while it's plugged in to power, and as soon as you plug it in to power, it immediately goes off, not back to 15%. you have to manually set it again.
so, obviously, they're making it a royal pain in the ass to keep it on for some reason. but once you get into the habit it's not that bad. and it seems to last 4 to 5 days between charges now, instead of 2 or 3.
last updated 2017-10-13 15:52:23. served from tektonic.jcomeau.com