Not getting the advertised run time

[etc]

I have a couple of well known 3W leds (Princeton Tec Apex, Fenix L2D) and I feel I am not getting the run time I am supposed to be getting.

Especially true for "High" or turbo mode.

 

[PhantomPhoton]

Well first question I'm asking is what batteries are you using? Not all have turned out to be created equal.
Also I'd say that most manufacturers give inflated runtime estimates, instead of real world numbers. The same is true for lumens out the front too.
Constant use or incremental use?
Using it at extreme temperatures? Alki batts don't like cold very much.

 

[Gunner12]

If the runtimes were tested, then the runtimes were probably made with the best Lithium or rechargeable battery.

Check Flashlight reviews(L2D-CE, Apex) or Chevofreak's or any other review's runtime graphs for more accurate data.

 

[etc]

I use the best cells I can find. NiMH 2700 mAh like Maha Powerex. Eneloop is good to but doesn't have the run time of Powerex due to being 2,000 mAh.

 

[WadeF]

Looks like lithium AA's last the longest, longer than NiMH's.