Those packs are providing the power for the heavy duty strobes (flashes) they used to light up the caverns. Check the page they link at the top of the first one for a good look, in the first pic.
The man is full of energy, in all forms! Some less friendly than others. /ubbthreads/images/graemlins/icon15.gif Just look on his web site at what he considers food! I wouldn't be surprised if one of man's first successful sustainable fusion reactions doesn't occur within 4" of PK's navel.