If you fit the 12v parallel charge setup to your chair, and matching Anderson to your cars dashboard then you dont need jump leads.
The chairs 12v anderson system can start the van while you sit in the drivers position.
The van can charge the chair once running. (Unless belt snapped!)
The alternator belt snapping will mean you dont get to drive far before the ignition system and anything else turned on soon wipe out your vans 1 battery. But again theres another two that can be connected via your chairs parallel charge connection to get you home with 3x the capacity to go at
Just an idea. I love flexibility and contingency plans! Mine already rescued me when I left some stuff on and came out of the cinema with no van battery left. I connected to the OUTSIDE anderson to power the door/ramp down. Then connected to the INSIDE Anderson to start the van. Then let the vans alternator charge all three as I drove home problem free.
See
http://www.wheelchairdriver.com/charge- ... om-car.htmAnd then here for parallel setup:
http://www.wheelchairdriver.com/faster- ... arging.htm