FYI a second battery can be added. What you are really looking for (and this is information I got from Phil when I was looking at a Pajero) is the winter package, which along with the 2nd battery added LSD, quick start glow plugs and some other upgrades. I believe the winter package is indicated by an orange sticker on the rear door.

1991 Mitsubishi Pajero XP TD LWB family hauler.