Thanks for all the replies, it's interesting that this market segment still doesn't seem very well serviced.
I am well aware how 'easy' it is to carry 'a spare' battery etc, but when you step back and look at this as a design solution, it sucks. It requires management, forethought, a system to separate used and fresh batteries, and at the end of the day it still means fiddling with small parts IN THE DARK when the battery dies and you have to change it. Quite honestly, if the SHTF, I have better things to do than fartarse around with battery polarity and dropping things in the mud. What I don't get is the willingness with which otherwise prepared, 'self sufficient' characters will rely on such a suboptimal solution and an external supply of some critical resource.
Also, say you're camping, you get up in the night to go to the toilet. Do you carry a spare battery with you? Because I sure as hell don't. Maybe you're far too organised for that, and you've already 'audited' your flashlight and you know exactly how much juice you have left. Good for you. Again, I think I have better things to do with my time. Besides, what if the SHTF at that exact moment, you're away from your camp with nothing but a pair of boxer shorts, a roll of toilet paper and a flashlight that's minutes from death?
I also have to take issue with this idea that somehow cranking it is a chore that takes time and energy away from other things. It really isn't. My $5 special obviously has internal gearing that makes the handle quite resistant to turning, but you can hear the internals spinning quite fiercely with each crank. I've never felt the need to crank for x number of minutes, just doing it for a few seconds whenever I get the urge, before and/or after use seems to be enough to keep it charged. I used to spend just as long polishing the fingermarks off of my expensive lights. I might not want to use this kind of flashlight for hours at a time, but I rarely need to. A few seconds of light here and there to find my path, illuminate a hazard, find something etc is all I seem to need, but when I need it, I need it.
I don't see any reason why a hand crank must NECESSARILY mean unreliability. It's a few moving parts, sure, but as a species we've been getting pretty good at moving parts over the last couple of hundred years. Plus, as StudFreeman suggests, if you incorporate a rechargeable AA cell you have the option to carry a spare to cover crank failure. And lets face it, crank failure is possible, but battery death is guaranteed. And in a zombie apocalypse or castaway scenario your batteries WILL run out, while my crank MAY fail.
On the other hand the beauty of a crank (or shaker) is that it is a simple motion that pretty much anyone can do, and you can do it in the dark with instant results. I'm not trying to lift a man up a ladder, I just want to see.
Anyway, as well as all the good suggestions here, I found a company called Freeplay that is at the pointy end of kinetically-powered devices, simple and reliable for third-world applications etc. I'll continue to digest the various choices and report back with any thoughts and experiences etc.
And remember kids, just say 'no' to batteries...
. I'm interested in which light you go with.
