A while back, someone on the Vanagon list, Jeff S I think, recommended a
batter booster that he bought from the Snap-On guy who came by his shop. I
looked around on Amazon and got a decent buy on that same or similar, I
don't recall the exact name of the one recommended.

Anyway, this thing is about the size of three decks of cards side by side.
It comes with every kind of connector you can think of including iPhone 5
and 6. It has a built in flashlight, a USB port. It will run a phone in
heavy use for days.

But, most importantly, it will start a car, even my diesel 1.6, with a dead
battery.

Very good insurance, if you go the places I go, for $100.

Jim