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 dropped this in another thread, I was thinking of sticking one in an old chrome bullet style headlight for that old school look... Well that and to see how bright they really are.

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.

Under $200 will be tough for high quality commercially available lights. You might look at the Cygolite DualCross series. Anywhere from $140-200 depending on the battery type you choose.

https://performancebike.resultspage.c...om&w=dualcross

For small size....
Helmet mounted nightrider minewtx2. Perhaps not quite as bright as your 20w halogen but tiny and 3.5-7 hrs runtime (high/low).

A pack of rechargeables, a recharger, and a bunch of Fenix L2Ds.

You can make your own LED light with parts available here.
https://www.luxeonstar.com/index.php
Pick your LED and select your choice of lens and matching holder for it. I prefer the Fraen elliptical beam pattern.


I built my 1-watt LED with lens and holder in a 1-inch PVC coupler. Large childproof prescription bottle caps are a press fit and hold a clear lens on the front and aluminum on the rear with a grommet allowing the wires to pass through.

I do a lot of nighttime riding so I went with DIY hybrid lighting system. This was the reason for using a 1-watt LED. It only draws 350mA so a dynamo can easily supply it with more than enough current. Too much current if you try and connect it directly to the dynamo! It generates 500mA, which would reduce its life. Adding a battery gives that excess current some place to go and allows the LED's to continue to illuminate even when stopped or the dynamo is disengaged. Here is the circuit I use.

Switch S2 is only needed if you use a hub dynamo. S1 can be opened with the dynamo engaged allowing you to rapid recharge the batteries with 500mA. With the dynamo engaged, riding above 8-MPH, and the LED's on up to 120mA is recharging the batteries. This requires disengaging the dynamo occasionally to prevent overcharging the batteries if your not stopping very much.
Here is a photo of my test and reliability setup.

Note the modified 9.6 R/C battery pack straped to the rack. Thats 2.4 Amp hours of current available to operate the LED's for several hours without help from the dynamo.

I have read that Fenix's may have problems with the Turbo mode. Basically, left on for too long and it will fry it. Have you considered Wolf Eyes? Wolf Eyes are available at PTS Flashlight, but are meant to be much sturdier, and brighter. They have Q2's out now.

Fenix, ~110 lumens, at Turbo, if it stays on...and don't fry the light
Wolf Eyes Tactical Grade ~150-160 lumens rated for 2.5h

https://www.pts-flashlights.com/produ...9-104-110-6333

Also, consider not using lockblocks, but using my method instead:
https://www.bikeforums.net/electronics-lighting-gadgets/341687-finally-really-solid-bicycle-flashlight-mount-photos.html (POST 17) GRUN.

The other option is to get the Dinotte 600L. That would be my option.

https://www.coloradocyclist.com/product/display/90150/
Princeton Tec Switchback 3 is still on closeout at Colorado Cyclist for $215 plus shipping.

https://www.gearreview.com/2007_led_lights.php
You can read light reviews here and look for the best deals.

The Dinotte is a nice light, and is very lightweight ~200grams for the light + batteries (AA version). So, that makes it a great helmet mounted light.

Awesome, definitely a lot to check out here. My DIY instincts are definitely being appealed to once again, but it does look like there are some pretty slick storebought options out there too. Thanks guys! I'll keep everyone posted with what I go with...and in the mean time I'll try to remember to get some pics of my current set up going, cause it's really quite bright.