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Old 10-04-07 | 12:33 PM
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cyccommute
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From: Denver, CO

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Originally Posted by mtn_mojo
Hi everyone. So I've been running a homebrew light system on my commuter bike, a 20W halogen MR16 powered by a 5.5aH 12V SLA battery. Other than feeling like I'm carrying a bowling ball around, the light has been amazingly bright and reliable, I can run it to almost 3 hours at a stretch.

Problem is, aside from the weight, I can't very easily move this setup between bikes. I keep the battery in one of those rectangular rear rack bags, which is also quite handy for storing my extra clothes and lunch and such. However, I recently started taking a continuing ed night class and that bag just doesn't fit books and such. I hate wearing anything more than a light messenger bag on my back while riding, so I have been coveting the rack space for bungeeing my book bag down like I used to do when I was in college. Also, I would really love to be able to take some of my other bikes out riding at night without figuring out where to put a seven pound battery.

So, can anyone suggest a good, portable LED setup that won't break the bank? I don't want to spend more than $200, and would love to spend much less than that if possible. I've been looking into homebrewing an LED setup, but that seems to be a bit beyond me technically at the moment. So far I've been really intrigued by a dual Fenix L2D flashlight system, or the Dinotte 200L. Currently leaning towards the Fenix lights, since a couple lockblocks seem easy to remove and I love the idea that they serve double duty as actual flashlights.

Any other thoughts or suggestions out there for me? I realize there are a number of threads along similar lines, but I didn't want to hijack anyone elses specific requests for info.

I'd suggest changing the battery. Carrying a 7 lb lead brick is a bit much. You can get nearly the same Ah rating out of 2 of these wired in series for a faction of the weight and size. Put them in a Cage Rocket box to free up space.

Two 7.2V batteries in series will give you 14.4V which is a 20% overvolt on your MR16. If this guy's numbers are correct
(which I have a little doubt on his MR16 numbers), you'll boost your output way over anything that you can buy in LED...no matter how much you spend. And you'll have a 2 hr run time...not too bad.

And way less than $200.
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