remote battery pack?

[sardo_67]

i'm looking into starting my first custom flashlight project, i have an AR type rifle and want to mount a weapons light on it with over 500 lumen in an LED. i want to make this about the length of a 6P with a turbo head, i have seen air soft guns that have fake IR laser pointers on them with hidden battery packs to run the gun. would that be possible with a light? i could put any type of batteries in it that would be needed but how would i wire it and use a tape switch for on/off?

http://www.airsoftpost.com/product_info.php?products_id=30628
http://www.airsoftpost.com/product_info.php?products_id=29061

something like those but with different batteries