I once tested my Zebralight H501 with 0.3 lumen moon mode in a dark forrest. That small amount of light was quite enough for walking and not stumbling around. Of course no running and walking carefully and I only saw a couple of meters ahead but still doable.

Yeah, those of our ancestors who had better night vision tended to survive and those who didn't, didn't.

I once read an article by some anthropologist (sorry, reference long since lost) who theorized that the average intelligence of "primitive" man was higher than the average intelligence of "modern" man. His reason: nature is brutal and the stupid don't survive.

Stories like this seem like they support his theory. . .

A good modern flashlight has a lot to commend it, and a spare is sensible just in case.

But it is worth remembering that until only a generation or two ago, that people walked around after dark with only a wind resistant candle lantern, or an oil hurricane lamp, and managed just fine.

My hiking light back in the day was a PT Attitude with a 70 hour runtime. I changed out batteries on a annual basis, even though they were still servicable.

If your EDC light is like mine (Fenix E01), and doesn't have a dimming grace period after the regulation drops out (with Li primaries), it might be a good idea to change it out periodically. Otherwise, you might be better served by just keeping a spare battery handy.

Invalid post ,disregard.

Excellent battery choice. 10 year shelf life and usually three times the runtime of alkalines. But they are pricey. Rather than just throwing them out when they have been there a "while", why not invest in a good battery checker like the ZTS and just check them periodically. Even if you confirm plenty of life left, carrying a spare as suggested above is a great idea and there are some great containers out there. Regardless of the life left in the battery in the light, an accidental activation left unnoticed for a couple of days will kill any battery.

That's a good idea. I should get a good tester.

I recommend this one: http://www.batteryjunction.com/zts-mini-mbt-r3.html . Most battery testers just check the voltage. Only a pulse-load tester will give you an accurate reading.

No affiliation with Battery Junction or ZTS except as a customer.

This is proof that Darwin was right.

I'd buy a cheap multimeter before buying a dedicated battery tester. A multimeter is more versatile, and you can get the testing done just as good. Here's a Youtube video to show you how to do this correctly with a load:

http://youtu.be/HcikzMG7mMU