what is draining my battery?

don’t use the van that often…. it was in the body shop last week getting the bumper repainted and i had to jump start it in order to get home. took a bit of a detour to get home (approx. 45 min journey).
gone out side today and the it won’t start…

battery is approx 8 months old. no interior lights burning (they run off the leisure battery any how).

what could it be?

Are you sure its charging?
Check the voltage across the terminals and the output wire if you have access to a loop ampmeter

don’t use the van that often

maybe batteries like to be used/kept fully charged?

dodgy/faulty wiring in your switch over kit

Dead battery

faulty alternator

faulty alarm/immobiliser.

Is it a camper with switchable power/batteries – check if the switch is on leisure or main for charging .

Also did they disconnect the battery to do the work? A dodgy reconnection is a possibility.

Check earth strap from the block.