Flashlight Economics 101

[rlhess]

Hi, I had little to do with Excel open on my computer this afternoon, so I made a quick attempt to estimate running (not including purchase) costs based on battery and lamp life. Here is what I found:

Incandescent Lights
Surefire E2e $4.90 per hour (2-123)
Brinkmann LX $5.80 per hour (2-123)
UKE SL6 $2.30 per hour (6-C)
6D Maglite $1.00 per hour (6-D)
Minimag/Nexstar $0.70 per hour (2-AA)

LED Lights
Lambda Illuminator $0.30 per hour (2-AA)
Inova X5 $1.10 per hour (2-123)
Arc LE $0.10 per hour (1-AAA)
PT Aurora (hi) $0.15 per hour (3-AAA)

Of course, personal tastes may change this. The X5 can provide some output for much longer. I've used the low-end of the range and I'm using the prices I've been paying at DigiKey (plus shipping) for alkalines and $2.79 each delivered for 123s.

Cheers,

Richard

 

[flashfan]

Very interesting. If I may ask, what kind of alkaline batteries do you use (brand? regular? ultra? max? etc.)? And do you have any figures for some of the brighter lights, eg. SureFire M3, M6, Underwater Kinetics Light Cannon, etc.?

Thanks for sharing the info.

 

[rlhess]

Sorry, I don't have figures for any other lights--I calc'd for the lights I have or soon will have (the SL-6 is on order).

I use Panasonic alkaline batteries sold at www.digikey.com I buy them in reasonable quantities and used the following costs per cell:

123 AA AAA C D
2.79 0.38 0.43 1.20 1.30

There is another measure that is interesting...
COST PER THOUSAND PEAK CANDELA HOURS

This creates a bit of a difference:

Incandescent Lights
Surefire E2e $3.77 per M-cd-hour (2-123)
Brinkmann LX $2.31 per M-cd-hour (2-123)
UKE SL6 $0.46 per M-cd-hour (6-C)
6D Maglite $0.37 per M-cd-hour (6-D)
Minimag/Nexstar $1.35 per M-cd-hour (2-AA)

LED Lights
Lambda Illuminator $1.22 per M-cd-hour (2-AA)
Inova X5 $14.88 per M-cd-hour (2-123)
Arc LE $3.44 per M-cd-hour (1-AAA)
PT Aurora (hi) $3.23 per M-cd-hour (3-AAA)

NEITHER value alone is a reasonable test, but both are good to know. For example, the X5 stands out as being very costly to run for its light output.

These figures contain MANY assumptions and are based in part on my measurements and in part on my reading of published data.

To answer the specific question.

For SureFire units the M6 is the limit, so I added that into the spreadsheet and it's $18.50 per hour with the LOLA and $52 per hour with the HOLA, assuming 15 hour lamp life. HOWEVER, the cost per thousand candela hours remains about the same in the $4.00 range (I haven't measured an M6 and I'm using assumptions based on lumen output and the measured candela of the E2, so it might even be better with the larger head.

Hope this helps!

Richard

 

[Alan]

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by rlhess:

Minimag/Nexstar $1.35 per M-cd-hour (6-AA)
<HR></BLOCKQUOTE>

Hi Richard, you repeatly use 6-AA for Minimag in your posts, is it a typo or I missed something

If you use rechargeables for your freqently used light, your cost will be changed significantly. Try NiMH on Tec40 with cheap Krypton 3D cell bulb, you might get astonishing figure especially with its brightness.

Alan

 

[rlhess]

Alan,

Thanks! Yes, of course rechargeables offer a significant cost decrease--they aren't available in the 123 size, however. I also don't like the self-discharge of rechargeables--I need a flashlight to work when I grab it and we won't have the discipline around our house of recharging every month or so. If I used a light daily for some period of time, yes, I'd use rechargeables.

Thanks for pointing out my Copy and Vaste error (well, it is Vaste if it's ctrl-V <smile> ). I've edited the two posts.

Cheers,

Ricahrd