The second thing is how to "open" the main relay like the bike is running.
I use a key-switch you can see on the photo at the right side under my seat.
I have cut the orange/red cable at pin 1 to the sevcon. it is the supply for the Sevcon.
In one position of the switch i connect the orange/red line as original (drive mode)
The center connection of the switch is running to the Sevcon the switching contact is the incoming cable (from MBB).
At the other contact of the switch I have connected the Battery + (tapped at the Anderson). If I switch the Key-switch to this position the Sevcon is powered on and the relay opens the high current path to the battery
The rest of the bike is off! (of course the BMS is always on).
You can see the red Anderson connector for the charger and the green and blue small Anderson in front of the red one there is the battery + and the white BMS control line to my charging box.