Simple answer is YES.
I have the leisure battery on the RH side and the driving battery on the LH side.
Dont ask me how its done, it was done before i got my van.
There is i thick red (thickness of my thumb) extension lead for the starter lead, and the rest have been redone as well, the main problem is there is no securing bracket for the battery, but still has passed the mot for the last 3 yrs i have had it.
Im thinking about changing it back around cos when i need the take out the leisure battery i need to remove the air filter assy.