Ultracapacitor LED Flashlight Charges In 90 Seconds

Iddo Genuth writes "The California based company 5.11 Tactical has recently introduced a new innovative flashlight — 'Light For Life' UC3.400. Unlike regular flashlights requiring constant battery changing this new LED torch offers a rechargeable battery that can be recharged in as little as 90 seconds using ultracapacitor technology. Various military and rescue units might benefit from this new development, ensuring them a light source at all times."

Limited usefull information.

[B5_geek]

VapourWare: Lights will be delivered on a first come, first serve basis in early 2009.
90-minute runtime
270 Lumens

The claim is 270L for 1.5h, using three emitters. It looks from that close-up of the head that Crees are used, so most likely XR-Es. I'll use a rough 100L/W for my estimates.

270L/3 = 90L per emitter

90L corresponds to about 350mA at 3.2V (very roughly) from an XR-E.

If*Vf*emitters*time = energy

0.35A*3.2V*3*1.5h = 5.04Wh

So, the supercap has about 5Wh in it (again, very roughly).

The above assumes 270L at the emitter. Let's say it's 270L OTF, which would mean around 360L at the emitters.

360/3 = 120L per emitter

120L corresponds to, say, 450mA at 3.3V or so.

0.45A*3.3V*3*1.5h = 6.7Wh

This more optimistic estimate (in terms of both energy storage and lumen claims) puts us at a little under 7Wh for the supercap used in the light.

Let's see what we get with a common AW 18650:

3.7V*2.2Ah=8.14Wh

So, this flashlight's power source has around 62% (pessimistically) or 82% (optimistically) of the energy of an 18650, but is several times the size.

I think I'll pass on this one.

Re:Better be a mighty fine flashlight for $170

[computersareevil]

Ultracapacitors have very low self-discharge rates. Lower than most battery technologies.

Re:Better be a mighty fine flashlight for $170

[Gary]

I do some work as a volunteer officer and the flashlights you get for $10 just don't compare. Most police-style flashlights are built much more ruggedly and are significantly brighter. When you find yourself facing a hostile assailant with nothing but a flashlight in your hand it's nice to know that the flashlight can function as an object for self defense if necessary, not to mention break-and-rake on car and house windows. Also the extra brightness is a safety feature too. Obviously searching a dark area with a brighter light is safer, assuming you need to use a light at all, not to mention being able to temporarily blind someone whose eyes are dark-adjusted.

Then of course the price is related to the market size. Not many people need a flashlight with these extra capabilities so less market = higher price.

Re:90 seconds!

[Elder Entropist]

Except those 90 seconds.

In which you will be eaten by a grue.

You should still be fine if you don't move more than once during those 90 seconds. You have to move twice in the dark to get eaten by a grue.

Re:Limited usefull information.

[jdong]

Oh without a doubt in my mind, from my experience with being a flashlightaholic (my collection of lights totals about $2000-ish), 5.11 is playing a few common low-grade marketing games here:
(1) Advertising emitter lumens instead of out-the-front lumens. The number almost certainly doesn't account for losses in the reflector.
(2) Advertising emitter lumens at peak driveable Vf and current. Almost every vendor except the Inova T-series and INFORCE (military) series does this -- they put a lumens number on the box that is taken from the spec sheet. Then, they do not actually drive the emitter at the power required to produce this amount, usually because it generates too much eat or returns too low of a runtime.
(3) Advertising useless runtime. My NiteCore D10 is a 1xAA Cree Q5 based emitter. On a 2000mAh NIMH cell, it produces a little over 2 hours of full DC-DC regulated brightness. Then, the output tapers off and goes into a "moon" brightness for 24 hours so you can find your next set of batteries. So, does this have 120 minutes of runtime or 24 hours of runtime? I'd say realistically the former -- Nitecore advertises the former (runtime to 50% brightness) -- but I've seen far too many products in this industry advertise the latter.

Bottom line is Inova's new INFORCE series military lights produce 150 or so out-the-front lumens and the light costs close to $200 MSRP. I don't see this product performing even in that ballpark. Press release = marketing speak; call me back when a reputable source produces a runtime graph and output graph.

Re:Limited usefull information.

[sslo]

Actually, your calculations are even further off than I thought. Rather than multiplying the 60 minute runtime (on low) by the 270 lumen brightness (on high) from the 5.11 data sheet, you have somehow posited 270 lumens for 1.5 hours - which seems to have come straight out of thin air.

This means that your calculations are off by a factor of six.