As most people know, lithium chemistry batteries prefer being used between 20-80%. I've set up a Macrodroid macro on my Ulefone Armor 8 to warn me when those parameters are reached by voice if the screen is off or by a notification if not.
However I have also set up a macro that at 85% does various things (bluetooth disconnect, vol+) and then tells Google Home to switch off the charger (charger being a zigbee socket running various phone chargers). It works perfectly
If you get the syntax right you can use Macrodroid to tell Home or Alexa to do various things and amazingly enough this will work fine.
I don't know if anyone else has tried this but it might be of use to people on here, since theoretically it should be possible to set up various (phone) macros to control various things by voice - and geofencing the macros (only run at home) will stop them activating when you're are out or at work or whatever...
Let your phone do the work..