Hi there,
I've got an old vistalight nightstick set up (NiMH 2200mAH battery + 10W bulb) which really isn't bright enough and only gives me an hour of runtime. I was wondering if there was any way I could hook up a more powerful LED light to the battery pack, and if so can I expect a longer runtime?
Thanks for any advice.

What voltage are your batteries?
As I've just finished making a pair 500 lumen LED lights for someone & know he dosen't want them.

Good question… the only voltage info I can see is on the vistalite charger – output = 7.5V. any use?

Yes the lights I've just made are designed to run on any battery up to 8 volts, they are tiny, just 20mm diameter & 50mm long aluminium bodied Cree R2 LED units, all they need is a bar clamp or you could mount one on your helmet.
Let me have your email & I'll let you have a better pic.

vista batteries are 6v. not much room in the casings for a mod. you can get brighter bulbs online, do a search. new batteries will be cheap, try componentshop etc – go for the remote controlled car / plane race pack batteries. you may need a new charger too if the sticks were nicad rather than nimh.