Here's something I've been waiting to find for cheap for a long
time.  Could be used in the van for what???  Use your
imagination.  Maybe lights or fans that only need to come on
automatically at certain times of day?  Also thinking this could be
great for use in solar applications on and off the van.  It could
disconnect a small inverter (mind the capacity of the contacts in
this timer) from the batteries except when needed to avoid that idle drain.

http://www.banggood.com/DC-12V-Mini-LCD-Digital-Microcomputer-Control-Power-Timer-Switch-p-909362.html

Edward