folks, a Vanagon is a crappy platform for an EV.  EVs should be light and/or
aerodynamic.

To power a vehicle size/weight of a Vanagon with batteries (and have the
batteries last a decent amount of time), plan on about 700-1000 pounds of
lead acid per gallon of gas range.

i.e. to go 30 miles on battery power you'll need 1500-2000 pounds of lead
acid batteries.   Do you want all that weight in your van?

Lithium batteries would weigh half as much, but cost triple the price.
(still way better overall)

To get an idea of what is possible with homemade EVs, check out
http://www.EValbum.com
....and by the way, most owners exaggerate their range claims.   NEVER buy
an EV without first testing the range yourself.