Hi John! Great input.
A agree on the paradox but... There is a walkaround within the circut.
I agree with you and sometimes simlicity is the best.
I think that I will combine two switches on a PCB. one push for the pi shutdown thowring in a led to show when it is off and then a switch for the batteries.
The main advantage is still two. first: No need to struggle with SSH and cables.
Two: putting it on a PCB for easy attachment to the robot with skrews or hot glue.
Now here is the relay solution:
"Latching relays keep their switched contact postion without power, this makes them very suitable for low power situations such as powering from batteries or where no permanent power is available. The best way to imagine a latching relay is a house light switch, you briefly push it to turn on (it remains that way with no power) until you push it to turn off in the opposite direction. Normal relays require a continuous voltage to keep the contacts closed, bistable versions do not, they "flip flop" between a "set" and "reset""
Now If I understand this correctly in my wicked mind:
Relay in position 1, Button pressed, Script turns down Pi
Circuit indicates that Pi is down or a time delay and changes the relay to position 2, cutting off batteries.
Position 2 has practicly created another circuit. Now button can take power to move the relay to position 1 and board and Pi is powers up.
Where do i go wrong?