My contingency is a pair of jumper cables.... A/T kasi.
OOT: Back in my youth, Diesels can go everywhere without a battery. My dad's then "big body" Ford Fiera went several weeks with a dead battery. Tinutulak lang nung mga pahinante. I know because yan din pang hatid-sundo sa akin sa school for a while. I had to seat up front because it's a delivery/closed van. In retrospect, that infernal vehicle had no seat belts, no doors, and the only thing between you and the outside world was a 1-inch stainless hand rail.
^ The Perkins diesel that used to be a genset motor. Most diesels today could still run without battery esp those with mechanical injection pumps.