Great answers! I have been using a 6V 3W headlight. I use a LA 5AHr battery. My light draws about 1/2 amp/hr. Theoretically I should get 10 hours out of my battery. NOT! I have had my system for quite a while. I chose the lame 3W halogen to get more run time. It really isn't very bright.

I'm looking at a 12V battery and light set-up now. I also think the NiMh batter is a better choice with the Lithium being the best (but most expensive) battery. I'm still looking at lights.