Surprisingly effective LED "shakelight"

Our "closet Flashaholic" doorman showed me a shakelight he bought on the street a few days ago for $1.00. I've seen several shakelights over the years and haven't been impressed. This light surprised me.

It is quite compact and light: 7-1/8" long including rear lanyard holder. Bezel is 1-1/2" diameter and the body gradually tapers to about 1-1/8" at the tail. Weight is 2.9oz and activation is via a sliding side switch. The body is semi-transparent plastic and attractive but rather cheap-looking. (Whaddayuh want for a dollar?)

A plastic lens focuses the LED into a small spot with minimal sidespill, similar to the current KL-1 (but of course much dimmer). There are no identifying marks of any kind on the light, not even "made in China", but a large number 14 is visible through the semi- transparent body.

Maybe I haven't kept up with shakelight evolution but the performance of this light impressed me. When freshly shaken its total output was about equal to a "conventional" ARC AAA running on an L92 (lithium primary). Although its total output was significally less than than the new ARC AAA-P, its tightly focused spot (about 9" at 5 feet) was brighter than the AAA-P's hotspot, and could be superimposed upon it. The spot was surrounded by a dim corona which gave the beam an overall diameter of about 19" at 5 feet. Although most of the light was concentrated in the spot, the beam was more than adequate for night walking.

I had always assumed that shakelights provided a minimum of runtime for a maximum of "shaketime", but that didn't apply to this light. I bought it, used, from my dooman who said he had shaken it "a few times" before he came to work at night. I gave it 20 very casual nearly effortless shakes, shined it around for a minute or so, then went to bed and didn't turn it on again until last night after it had been off for about 24 hours. It lit immediately with a diminished but still usuable amount of light . Then I gave it 20 more very easy and relaxed shakes and compared it the two ARC AAAs as described earlier.

I believe that even if you were injured and in an emergency situation you could keep this light going for many hours, or even days by just giving it 3 or 4 gentle shakes from time to time. Evidently this technology has advanced considerably since the early days and a tougher waterproof version of this light might be a very handy item to keep around the house.

Brightnorm

have a look at this shake light.

http://www.aquamarineuk.com/product_info.php?products_id=544&osCsid=ab2bdc1deca7ec2982dffd8ecce999c3

I bought two a few years ago they work really well.

you can use it as a normal flashlight as it has a dual switch

turn oneway and it uses shake power storing it in a very large capacitor.

I have had a couple of other shake lights over the years and the storage capacitor is usually quite small.

this one is approx 20mm wide and 8mm deep.

also this light takes 3 x AA batteries that you fit in a battery holder in the base , you just turn the switch the other way.

it has two leds for illumination, one led on with shakepower and two with battery.

regards.

Look directly behind the LED and see if two coin cell batteries are there. If so, that's what it's running off and the shake mechanism is probably a fake.

nikon said:

Look directly behind the LED and see if two coin cell batteries are there. If so, that's what it's running off and the shake mechanism is probably a fake.

Click to expand...

Ive read about that. I'll be interested to know if that is what Brightnorm has in his light.
I've been considering a "shake" light as a backup for some time now.

2.9 ounces is the weight of at least half a dozen Fauxtons. I'd just stash some Fauxtons instead of messing with the shakelight.

I've yet to read about the typical lifespan of the capacitor used to store the charge. Capacitor life is greatly influenced by temperature. I wonder if a shakelight in a car would last as long as a lithium celled light, if kept as an emergency light.

After reading in another thread about the fake shake lights I was initially upset when I got home and my wife had bought 4 from a local grocery store. I left it on for 24 hours and it was still fairly bright (in its dim compared to luxeon sort of way) then I shook it for a few seconds and it was back to full brightness. It seems that the small capacitor in it can be used for power from shaking aswell as the coin cells. I am pretty impressed with this, as she only paid $6 each.

I would rather have a hand crank flashlight that generates much longer and brighter light than a shake flashlight. Also if I bought one it would have to be 100% crank power, not just regular alkaline.

nikon said:

Look directly behind the LED and see if two coin cell batteries are there. If so, that's what it's running off and the shake mechanism is probably a fake.

Click to expand...

It's hard to see the interior through the semi-transparent plastic but the LED appears set into a full diameter glued-in metallic disc. Directly below that is the circuit board but no visible batteries.

BN

I recently bought a "fake"light too before I had read about them. I spotted it's fake innards soon after getting it home, but for $3 it does actually work pretty well. On mine you can unscrew the bezel and pull the entire guts out as a subassembly. The coin cells are replaceable, the slug is not magnetic.
My girlfriend has a light with an actual magnet, a real coil, capacitor, 4 diodes and resistor. It also has the two coin cells but I want to investigate if the coil is hooked up in any useable way or if it's just one of the very elaborate fakes I've read about.
I did buy a real shakelight at Walmart. It's in the Boating Accessories area rather than with their flashlights. It works well but I don't think it's really worth the $11.88 price. I've never heard them mentioned here, I stumbled upon it totally by accident.