Concur - your battery should not get hot just running a simple lamp.
make sure your wiring is like this:

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The other switches can be used for whatever you wish, some people put leds/lasers in the flamethower nozzles that light up when you push the buttons on the side of the left gaunt.
On the original prop, the "paddle" switch on the left gaunt looks to me to be just a "greeblie" - it's not real.
But I changed mine into a real switch to control the red lamp (from the diagram above).
Also - I choose to match the prop pics of the right gauntlet and removed the two toggle switches on the side. I would guess they were used to turn on the flamethrower or something.