EC25 with 2600mAh 18650 can last for 1hr 30mins at Turbo 860 lumens setting? Possible?
SRT6 1hr 45mins… Time or temp step down?
At least Fenix PD35 states 850 lumens last only 1hr 15mins.
much closer to lygte-info.dk battery review.
What are the capacities of the batteries they're using?
Maybe they calculated it based on the 5000mAH printed on their UltraFire cell's label. 
and maybe it’s not constant brightness… ansi runtime is until 50% of initial (or 30sec) brightness if I’m not mistaken
nitecore specs are garbage. some models use a 3rd stage stepdown to boost the numbers as high as possible it’s ridiculous
even some max-lumens numbers are not true when using 18650
then on some models like EC2 even the min lumens is misdeclared
ANSI-NEMA FL-1
The amount of continuous runtime (in minutes) until the light output drops to 10% of its original value (measured 30 seconds after turning the light on)
Nowadays many top brand companies use boost or other branding names to tell you that after a certain time brightness will drop, just that they tell you it's for LED life protection which many times maybe does not even run at 3A in the case of XM-L.
Table 1: 2600mAh. I presume their own brand.
Table 2: SRT6 1hr 45mins - capacity not stated.