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."

Comments

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.