Yes the Prodigy goes into a low power sleep mode. I made my own "remove before flight" type of flag for my TV. I took a piece of cardboard and cut it about steering wheel size and wrote "battery on charger" on it in magic marker. Then I used a razor knife to cut a hole about three inches from the top and a slit out to one of the edges.
Now when I plug the truck in I hang the sign on the steering wheel and close the door. I figure that if I manage to get in, move the sign out of the way to insert the ignition key, start the truck and back it away while still plugged in, I deserve to damage the cord.
When I'm driving I just slide the cardboard under the front seat to be used later.