In my quest to find the best rechargeable cells for my SF lights, I recently picked up some AW LiFePO4's rated at 500mAh capacity and then put it to the test against Tenergy's LiFePO4 offering (rated at 750 mAh).
In anticipation of using these in a M3LT, the cells were tested in a Lumapower VX Ultra which has been stated to draw approx. 2.1A on high.
Starting/Ending V (IMR thrown in for comparative analysis):
AW - 3.78/2.95
Tenergy - 3.75/2.94
IMR - 4.18/2.73
I've found that the LiFePO4's come off the charger at approx. 3.8v but will settle down to about 3.5ish after a few hours or so. I usually run the cells down a little further to about 3.3v before shoving them in SF lights just to be safe but since the VX Ult was designed for RCR's I simply conducted the tests shortly after the batteries came off the charger.
Here is the result:
X axis = Time (Min) / Y axis = Relative light output
Test conducted w/fan on. Surface temp of light @ the head was 81.5F at start and never got more than 86.5F throughout the tests. EDIT: For the LiFePO4's, I actually shut off the light @ approx. 53 min as I didn't want to over discharge the bat's.
Given the oft exaggerated stated capacities by certain brands and how highly vaunted AW's cells are, I was actually expecting the AW's to do better but it seems it got bested by the Tenergy (even if slightly).
Disclosure: All batteries were purchased for personal use.