Capacitor crank light vs. capacitor shake light
Some people have asked me to compare the capacitor crank light to a capacitor shake light since I have both.
Last night I finally dug out my capacitor shake lights
Light 1 and
Light 2.
These lights had been in storage for more than two years. They were completely discharged; not even the faintest glow from the LED. Both took a lot of shaking (2 minutes +) to get a decent amount of light. Once they were shining, they both dropped off about the same rate as I remember from when I was using them originally. I'm guessing the light decay time constant is on the order of a few minutes.
Light 2 has a clear housing, so I could see the capacitor ratings: 1.5 F at 5.5 V.
Both Light 1 and Light 2 use lenses to concentrate the light output. It will illuminate a spot about 2 feet in diameter several feet in front. This to me is a good compromise between throw and spill.
Light 2 has a noticeable green tint. When I was first using it, I thought it had a cyan LED. As I used it more I realized that it was probably a white LED that has a green tint. I could still discern different colors when using the light in a dark environment.
Light 1 had a noticeable blue tint, primarily in the center of the beam. There are numerous artifacts in the beam (when viewed against a white wall), but in general use they were not a factor.
Both Light 1 and Light 2 would have been suitable for walking a path in pitch black night.
Then I fired up the
crank light. After having just shaken the other two lights (with extra shaking for the completely discharged capacitors), I determined that it is easier to crank than to shake. It seems like less effort goes to making more light. The crank light was putting out more light, and I think its time constant was a little longer.
Of course, these are all my impressions and highly subjective.
Conclusions:
(1) Even a completely discharged capacitor (over 2 years) can be recharged without any noticeable effects. It just takes extra shake/crank time to build the charge to where the light output is sufficient.
(2) The shake lights are extremely well made and durable. And they are completely sealed. Even the switch is magnetic so the housing is impervious to water intrusion.
(3) The crank is noticeably easier to work than shaking. It is a newer product with more advanced LEDs and possibly a larger capacitor. It outthrows, outspills and outlasts the shake lights. It is claimed to be water resistant. I have little doubt that it would stand up to some rain.
One of these days I'm going to get a digital camera with manual exposure capability and a time-lapse feature. Then I'll fire up all three of these lights against a wall and post a video showing the beams and their decay characteristics.
Until then, if you want a hiking-in-the-dark light, I'd say go with the crank. If you want to keep a light in a remote cabin, then consider either the shake or crank. If you want an emergency light in the back of your truck, go with the shake.
Others have pointed out that for an emergency light for your car or truck, any old LED light with a lithium battery is a good choice. I'd have to agree with that. But for absolute reliability in any climate at any time, the shake light will be hard to beat.