Lights for a night or a month?

I have this dream of a super bright light that will go all night without a battery change.  Too much to ask for?  

A side benefit of this quest is a light that will burn for, uh, weeks.  Yea, no BS here - doing GDR this summer?  Put one of these on your bars as the main light  and something silly light for your helmet (for around camp and nightime repairs) and you're good to go. 

These charts show the potential dual useage of this setup I've got cooking in my brain.

The light is run by the bFlex as mentioned in the last post.  The bFlex allows configuration of max current (light intensity), and within each setting there are 5 levels.  The light levels are listed on the chart as "lumens", each grouping of runtimes are values for specific battery configurations.  The battery weight is approximately 6 ounces for 2400 mAh.  Yea, kinda techy but that's how to read the chart. 

For the above chart, this shows that you can have 668 lumens for ~ 5 hours with a 12 oz battery.  That's twice the light I had on my head at Moab (and 320 was plenty).  392 lumens can be had for 11 hours with the same system.

Now, take a look at what happens when we throttle back the max current setting to 350 ma.

For reference, a single 3W Luxeon puts out about 80 lumens.  I used two of these for KTR this year and the night went great.  Throw was a touch short on the descents, but totally doable.  Looking at the light blue lines, at 123 lumens you get about 70 hours of runtime, while at 200 you get about 40.  GDR nutz:  how much weight do you typically allow for batteries?  It's certainly feasible to have a sub 2lb setup that will last the duration of the event, provided you finish in a month ;)  It's also possible to use AA battery packs and use expendible batteries...but not having to worry about batteries I'd think would be quite an advantage.

Keep in mind this is all within the same light but with different settings.  I don't think there is anything remotely close to these capabilities on the market...dunno why, that market space is soooo big ;)

The best thing?  The above projections are based on the P3 Cree and in a couple of days I'll have the P4s which are roughly 10% brighter.  When they show up I can turn this gedanken experiment into reality.

Published Wednesday, January 17, 2007 4:39 AM by Dave
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# @ Wednesday, January 17, 2007 5:09 AM

Look where you might turn up this year:
Bet you didn't even know.


# @ Wednesday, January 17, 2007 5:38 AM

Too funny! jimmyboy is outta control.

You going?


# @ Wednesday, January 17, 2007 7:19 AM

Great post Dave. Build me up a set when you get the recipe right. I'm sold.

Hope you're training's going well.

Mark Ewers - 2 old 2 go slow

# @ Wednesday, January 17, 2007 8:14 AM

Great post! I keep waiting to see pics of a truck full of aluminum bar stock and a CNC machine so you can crank out your own light housings. :)

dave byers

# @ Wednesday, January 17, 2007 1:57 PM

Put me down for 2!

Looks very cool I'm super impressed so far with the Cree Alex built me....

Looks like you could land a plane with that light!

Thinking about a solar panel to charge the batts but if you build one of these.....

Good golly!


# @ Friday, January 19, 2007 6:12 AM

Only thing I know about the Cool race is that it smells like SPAM. I never got an "invite" that I know of. Nice to be put on a list of people that actually don't suck.
I have been invited to all kinds of races in the last few months, but nobody mentions that I still have to pay to race and all my travel expenses. Hmmmm... not much of an invite.