I am due to change mine this year. I don't turn mine on until I am set up and turn it off when walking out.
If I have time to get to a tree and get set up, I have time to turn it on.
The way I use mine, it is never on very long, but I think I read somewhere that they have a sleep mode, in case you leave it on. I could be wrong about this and as I stated, I would not have ever found out in use.
Maybe someone else knows.