Dynamo ('wind-up') flashlights

What is the experience here/views on (LED) dynamo flashlights - you know the ones with a handle that you wind-up. There seem to be some coming out recently with reasonable output for not too much winding and which also charge your cell phone - at least here in Oz.:lolsign:

Be careful what you buy. There's a lot of crap out there. http://www.flashlightreviews.com/features/fff.htm

I bought a 3 pack at costco, and out of the 3, only 1 really worked for more than a few minutes. Everywhere I've seen them, they only work for a minute then dim to nothing. Of course if I knew then what I knew now, I never would have bought them.

I bought one on Ebay for $5.00 shipped. It has 5 leds and a output to charge cell phone. It was a heck of a lot brighter than my nightstar (shake light). You can use 1-5 leds at once. It was supposed to last 20 minutes, but it lasted longer than that. I really never bring it out with me because it is not waterproof and it looks like it probably couldn't take a fall with out breaking. I got very tired trying to recharge my cell phone too.

Before Xmas my wife sent me out to buy a few of these for stocking stuffers on sale at Fred Meyer. I went through 20 they had in stock in order to buy 4 that held any kind of useful charge for more than 2 minutes; most dimmed within 30 seconds. As it turned out my wife's sister had the same idea and gave us a set of two in a package from Costco. One will not hold a charge for more than 20 seconds of light no matter how long you crank it. The other is quite different and I just checked it and all three leds are bright with good throw and decent white light and its been over 10 minutes without any dimming. Here's the kicker.... I have not cranked it since January! If they were all like this one, I'd buy a bunch more.

How much power does this cranking mechanism really give off when you crank it?

They'd probably do better now that there's new LED technology out. Cree or SSC led and it'll be much brighter.

I had one of the lights but I tore it apart after I broke it. I also have one of the Grundig radio flashlights. What I found was that if it has NIMH batteries, they will eventually die because these batteries do not like to be in a deep discharged state for any length of time. With these types of devices, we seldom charge them all the way up and put them away. The Nightstar shake lights us a capacitor to store the charge. They don't degrade and work well for an emergency light.

Alex

...now over 30 minutes and still very usable light. I can't tell it has dimmed at all. Why can't they all be like this one? A useful tool to put in a kit bag; butt then how about longevity?

OK it is dimming. You can see from the post times how it is holding up. Again... I have not cranked on this since January. It is still usable and about as bright as my LOD-CE on medium.

I prefer the type that uses the mains powered "hand-cranking" device to charge up the cells.

I think they're called Not In My Hand cells.

these "cranks" make electricity in the same way a power plant does. its too bad they are flashlights with built in generator, should instead be generator with built in flashlight. a human can generate about 100 watts on a bicycle, that would charge your phone pretty quick!

the concept is good but thats about it....under sized battery and an even more undersized dynamo to charge the cells with

the only windup light I've seen that actually works is this, not exactly the typical off-the-shelf light

in case your wondering...the motor + flashlight concept doesnt work that well either

With 200+ hour run-times being commonplace among ordinary battery-powered LED flashlights, there's not much point in messing with crank-powered lights. The extra mechanical complexity more than offsets any perceived advantage in not needing batteries. They aren't any more reliable than battery-powered lights - In fact, their plastic crank, gears, springs, dynamos, etc. make them considerably LESS reliable than ordinary flashlights. Under protracted use, most of them WILL fail - often, when you need them the most.

If you absolutely have to own a flashlight that doesn't need batteries, any of the better quality shake-lights would be a much better bet. (Note that quality is crucial - some of the cheap shake-lights are really "fake-lights", built with a non-rechargeable battery that eventually runs down.)

It's a shame really as I wanted to send a torch to a child I sponsor but obviously buying batteries isn't a good option.

The main problem I have with anything crank powered these days is they have rechargeable batteries that go bad if not recharged occasionally. My old model BayGen Freeplay (no lights, just a radio) uses a wind-up coil that unwinds to provide power, so there's no "charge" per se involved.

PayBack said:

It's a shame really as I wanted to send a torch to a child I sponsor but obviously buying batteries isn't a good option.

Click to expand...

So send a good-quality shakelight instead!

Flashlight Reviews: Shakelights

Their ok for emergencies, After a while cranking your hand gets numb

Skibane said:

So send a good-quality shakelight instead!

Flashlight Reviews: Shakelights

Click to expand...

Yeah I might do that, thanks. I just got a bad impression of them from what was probably a poor-quality example.

Oh and great link, cheers.

i recently hooked up a $5 crank light directly to a seoul P4 and BLAM! 850ma to the seoul, needs a heat sink. thats like what 150 lumens from a crank light? well its enough to illuminate a whole room for sure. dont underestimate the power of a little crank generator, its usually the batteries that suck. i got it at christmas tree shop in MA. took out everything but the crank, gears, and motor. next ill try to use it to charge a 18650 li-ion. probably take a long time tho.