OK, I ran a new enegerizer alkaline battery. I compared the output to a P3D-CE on medium which is advertised as 40 lumens (its pretty close to this).
I have no light meter, just eyeballing skills here. After 1 hour, light was noticeable dimmer but not at halfway point. At 1hr 15mins, light was very dim(well below half output). I cut the test at this point.
Here is where it gets interesting...
After having the light off for a few mins, I decided to turn it back on. Great, its at max brightness again . It stayed at this output for 20mins... 30mins it was pretty dim again so I just went to sleep with the light on.
I woke up this morning, turned the light off, waited a few mins and turned it back on. Its at max output again . Left it on for just a few mins because I give up.
So how is the driver on alks? I have no idea. The light did get a little hot so I left it on the window to keep it cool. I checked it very 5mins.
If anyone have any ideas why its behaving this way. I'd sure like to know.