I'm just posting to see if anyone has done any thorough scientific testing of the most commonly available "top of the line" brand name batteries to test their various qualities and general fitness for LED light use. I'm already aware, from what I've learned so far, that Lithiums are the best for most circumstances, when available (and when you can afford it), but has anyone done an efficiency test to see if Lithiums are worth the very high initial cost (I've found that I can buy something like 3 sets of Alkalines for the price of one set of Lithiums)? I'm already convinced that Lithium is best for harsh conditions such as car trunks and glove boxes, but how about general and home use? Also, has anyone done a comparison of the internal resistances of the various big name Alkaline batteries such as Energizer's Titanium or Duracell's Ultra so that we might know which batteries would be best for the most high drain LED flashlights? Also is there a runtime difference between all the different brands of Lithium AAs or are they pretty much the same? Another useful test would be to test the big name batteries to see which ones would have a life advantage over the others when used in LED flashlights. With the new Arc AAA Flashlight coming out, it would also be useful to have all of the above data for AAA as well as AA batteries. While I'm mentioning the upcoming Arc light, does anyone happen to know if there are any manufacturers of Lithium AAA batteries anywhere or do they not make Lithiums in this size? I guess what I'm getting at with this post is to find out if anyone has tested the batteries that we use as thoroughly as the various LED flashlights have been tested. If someone were to compile all of this info into a chart form, I believe it would be immensely useful to all of us flashaholics for the next time we go to buy our next set of batteries to make sure we are getting the absolute best bang for the buck.