Oh dear. This one is tricky.

Well, as you've no doubt been told, there is a vending machine in the maze. If you have the coins, you can get fresh batteries there. So you have to find the coins, and find the vending machine, before your batteries run out and you wander into a pit in the darkness. This can be difficult.

The coins are in the west side chamber of the Hall of the Mountain King. (This is the same location where you met the snake.)

The entrance to the maze (there are two mazes, actually) is south from the west end of the Very Long Hall. Once you get inside the maze, you will see the dreaded "You are in a maze of twisty passageways, all different."

Don't panic! From that spot, go ne, s, and s. You should then be at the vending machine. Try drop coins. To escape from the maze, type n, u, sw, d and you should be back at the Very Long Hall again. Whew.

However, to get a perfect score, you need to never have to get batteries from the vending machine. (By losing the coins, you get aced out of the coins score value.) But once you have everything mapped out, a little strategy will enable you to complete the entire game before the lamp runs out of power.