I've done some more research on these things.

The vast majority have rechargeable batteries, including our $1 jobbie. The problem is that,exactly as you say, the rechargeable batteries have only a limited lifetime of recharges and the shelf lives of these batteries ain't that good, either. A quality capacitor can be recharged several hundred thousand times.

Here is one that apparently has only a capacitor, but I'm not sure I believe it.
http://www.associatedcontent.com/art...16.html?cat=15

And here's a site that hasa buyer's guide for these devices, including information about how power is stored:
http://www.modernoutpost.com/gear/bu...ashlights.html

After having learned what I've learned, I would not buy a "wind-up"light that has a rechargeablebattery for power storage. The thing is likely only going to last a couple of years, at best. Better to get a small led light and put these in it:
http://www.energizer.com/products/hightech-batteries/lithium/Pages/lithium-batteries.aspx
Notice the shelf life. We use these batteriesin an outdoor, wirelesstemperature-sending unit for the "weather station" sitting on our kitchen table. The batteries have lasted over 1.5 years in all kinds of weather, including -30 C. Energizer claims that these last 7 times longer than alkaline and I believe it. In a small led flashlight that is used only infrequently, they and the led "bulb"should last virtually forever.

If I were going to buy a realemergency "self powered" light, here's the one I'd get:
http://www.modernoutpost.com/gear/de...akelight60.php
It has no batteries whatsoever and is also supposedly waterproof. One minute of shaking supposedly gives 60 minutes of light.(100,000 60-secrecharges will therefore give 100,000 hours of light. 100,000 hours equals4,166 days, or 11.4 years, and, remember, these things can be recharged "several" hundred thousand times.)

 

i have the one that has a handle and u turn it... it doesn't hold much, prob a few hours if you turn it like a zillion times!