Posted on 18 Aug 2014
YOU might have a short in the 12V system somewhere. Check any "additions" to the van that were not standard. Ie extra 12V systems, radio if not dealer fit, motor mover etc.
Also check the state of your batter terminals. sometimes they can get corroded.
Also check to see if there is anything turned on when not using it. I found that the TV/FM booster was draining my battery when not needed.
if in doubt call a specialist