Greetings Jim, this is Kostas (Orion) from the SH forum.
I have been considering your query since the time you posted it in SH, especially a few days ago since I was about to donate some flashlights to the local Red Cross team.
But since the time of your first post, and only in a few months time things have changed. Now there is the MagLED either in flashlight or kit retrofit form.
For that many hours and at your budget it is about as good as you can get.
There are some complications though. The Maglite LED modules do not dissipate heat that well, so soon enough a temperature controlling resistor kicks in and limits current draw and output. But it stays this way and if you are happy with the final level you are GTG.
Also. Do not think that you can purchase Maglite LED upgrades and place them in other lights like the GI Military. Trust me I know. The module is thicker than the PR lamp it replaces and not many lights will accept it. Let alone that usually holders are plastic.
Other options? Terralux and Diamond 3W Led upgrades. On the Terralux I do not know, but I just this morning tested my DiamondLED for output drop-off. After 10 minutes of continuous on and up to an hour when I stopped it, light had dropped/stabilized at about 65% of the original (according to my camera spot meter). Spill remained of the same luminosity. BTW according to reports MagLEDs drop-off more than that.
See these links:
MagLED review:
http://www.flashlightreviews.com/reviews/maglite_mag-led.htm
In-depth MagLED review
http://candlepowerforums.com/vb/showthread.php?t=119665
Terralux:
http://www.terralux.biz/products/index.php
DiamondLED:
http://www.diamond-led.com (these can be found for sale as low as $15)
Other shopping options
http://www.batteryjunction.com -
http://www.lighthound.com
For some beamshots of mine:
http://groups.msn.com/clenchedteetharticles/flashlightbeamshots.msnw
Other Options no2. Go down to a 1W module. Terralux has the TLE-1 module. Seems compatible with any 2 cell lights. So you can retrofit plastic and cheaper hosts.
Other Options no3. The AngleLux conversion. Good work, but two downsides. It carries the host drawback of sipping water from the switch module. But I guess you have used one before and you know. And it does away with the filter option since there must be more room for the new reflector.
On the upside, it now hosts the new gen of LEDs, the Cree XR-Es and it is generously heatsinked.
Other Options no4. Go with the Terralux K2 or SSC P4 LED upgrades. The latter will be soon available from the batteryjuction site.
The big downside with all LEDs is the quality of their light. The White/bluish hue does not travel far outdoors and is contaminated by the surrounding city lights. But I guess you have heard/know about it. But for your runtime requirement there is no other way.
On battery selection. You are better of with D-cells. See why
3xC - 8350 mAh x 4.5 volts = 37.5 Wh
2xD - 18000 mAh x 3 volts = 54 Wh
In comparison 3 x CR123 - 1300 to 1550 mAh x 9 volts = …
Now I feel your real problem is you budget. Had you more bucks per light you could buy Surefire LEDs, especially the upcoming ones, that will fill your runtime requirement on low while having the high option available on demand.
How about this. Do I remember correct that you have been using Streamlight up to now? There are retrofits/upgrades for them too.
So you can upgrade them with a portion of your budget, buy 2D MagLEDs for the rest of the crew, and if some loose money is available buy a few Surefire G2s.
And do encourage your personnel to bring their own flashlight as a backup. Hope they soon enough become unrecoverable flashacholics and bright their high-end light to work!
Best of luck, kostas