They say "photographic batteries" when really they should say flashaholic batteries instead. Why do so many lights use them? Surefire seems to think its the only battery that exists on earth. From what I've read its amazing how fast the e2 can suck down batteries. I'm not trying to sound negative but I want a light that doesnt eat 5 dollars for every hour I use it. With a standard battery light you can get off brand alkalines dirt cheap and also have the option of using rechargeable cells. I guess maybe the reason I'm complaining is I want a Surefire quality light that uses standard batteries. who knows