I am having the same issue… I think I will have to try holding down the power button for five seconds to completely turn the speaker off when not in use...

When your Move is docked, wil it not get power from the mains? How can the battery be drained then?

It’s not drained but it can’t be good for the battery to be constantly on while docked, seems kind of pointless. What’s better is I keep turning it off while docked and it keeps coming back on

Sonos support has stated the Move is designed to stay on the charging ring when not in use.  No damage to the battery will occur.

Since the Move is designed to be part of an “always on” multiroom environment it's designed to be on -  if you have to turn it when you want to listen to music half the comfort of such a system is gone.

This must mean the battery ist designed to withstand the fact that de Move is always on.