High power LED bike head light with integrated heat sink

Step 9 Test Shots

This step just shows some various comparison tests for light output and beam pattern. The first set is in my basement, with the camera set on a fixed 1 second shutter time and distance to the far wall of 25 feet. The first photo is the scene illuminated by a bare 60W incandescent bulb in the ceiling. The second shows the same scene illuminated only by a 10W narrow (15 degree) spot halogen bicycle light that I built. The final pic is of the scene illuminated only be the LED bike light detailed in this instructable. It is clear that the output of the LED light is much greater. However the ability of the LED to put light in a specific spot is not clear. The optics need some work if a spot type light is desired. I plan on taking some outdoor beam shots when the weather is a little more cooperative. Stay tuned.

Comments

[baratacus]

You don't want to blind other people on the road with you.  Not only will you make motorists angry and endanger people by blinding them so they can't see, but you can be ticketed and fined for opperating a vehicle in a hazardous manner.   The flood light is great for off road applications where you need to see rocks and chuckholes, low branches... but for on-road, you need a focused beam for a light that intense.
It's the same reason  that motorists who put HID xenon lights in a normal lamp housing without a focusing lense get fined and ticketed.

Excellent headlight option.  Once focused, you can probably go with a less powerfull setup and your battery pack will last longer.  Lithium is the way to go for high power output in a small size.

[jmengel]

I disagree.  As a cyclist in a world built for cars I want to be seen. The brighter and more splash the better to increase visibility. I'm not advocating a blinding sun-like beacon but I can't see how the 25+ degree lens on my light is any more blinding than the headlights on any truck or SUV at eye level to a motorist in a car.  I've ridden with people who have lower powered and tightly focused LED bikelights and while they have a nice throw out to 100+ feet they are surprisingly invisible to oncoming motorists outside that 10 degree cone.  I prefer to see as well as be seen.  Case and point my latest tail-light project has 100+ lumens of wide angle (160 degrees at 50%) light which is way better than the common LED blinkies with a 15 degree pattern.  How many times have you come up in your car on a cyclist with one of those anemic red LED flashers clipped to their black backpack and pointing the wrong way so as to be practically invisible?  Really common around the colleges here and on the sidewalks which is a recipe for disaster.

Lithium batteries are certainly superior in terms of energy density.  My latest light has a low and flash mode which extends the battery life of the LiFEPo pack significantly.  Like the aforementioned tail-light project, I have been meaning to write this up in an Instructable but have not found the time or energy.

Stay safe!

[baratacus]

I agree that visibility is an issue, but putting out 600lm of light in an unfocused beam, That lamp puts out way more light than the 60 watt incandescent bulb in your photos.   If it's as bright as you indicate then that is an issue.  My car has old-school seald headlights and it puts out less light with the highbeams on than that LED light you built.  If that light wasn't focused it would blind anyone looking at it.  You would be visible, but the motorists wouldn't be able to see anything else after they were night blinded by your light.    If you want more visibility then a multi directional lower output light would be a good start. I think the 100 lumen tail light you mentioned sounds perfect, and would do good as a front marker light as well.  In california though, on-road, you would be fined for running a 600 lumen  light  without focusing it.

[jmengel]

Uhh, and keeping wildlife, an amphibious rodent, for uh, domestic, you know, within the city - that ain't legal in CA either. (Walter)

Standard halogen headlights perform in the 15 lumens per watt range.  Typical low beams are 45W and high beams 65W for roughly 700 and 1000 lumens respectively.  Sealed beams have compromised reflector designs but still put out a lot of light.  Just more spill.  So with your high beams on, your old school headlights would be putting out 3400 lumens total L and R.  Which is brighter?  Now if were talking a padiddle all bets are off.

http://www.sylvania.com/ConsumerProducts/AutomotiveLighting/Products/Halogen/StandardHalogenProducts/

Additionally, I think you are confusing the lumen rating and candela rating (http://en.wikipedia.org/wiki/Candela).  A 600 lumen light with a 10 degree lens would appear much brighter than a 600 lumen light with a 25 degree lens.  The focused light would have roughly 6 times the candela rating and be 6 times as bright.  As to which impinges more light onto an oncoming driver's eyes is a complicated function of the optics of the systems in question and the emission pattern of the LED arrays as well as the aiming of the lights. Similarly, the poor reflector of a sealed headlight and the broad spread of the design in general may make them seem dimmer (low candela) than a focused LED but the headlights are still putting out a heck of a lot more light than the LED bike light.

So let's just agree to disagree and I promise not to ride with my light in CA.

[baratacus]

I don't dissagree at all.   The police here in my city are ticket happy when it comes to unfocused headlights.   They are'nt very concerned when it comes to satndard bike lights because they don' t typically put out more than 50 lm's of light.  I think a flood will provide you with much more visability than a spot.  I think with your light it may require some focusing for the law enfrorcement  officers to be ok with it.   That of course is pure speculation based on the sample pictures you provided.   Personally I intend to make one of your lights for myself, cause it's just too damn cool a project not to build.   When I do, I'lll be able to see first hand whether or not focusing the light is a concern.   focusing the light  is a very simple matter, and if I do feel it's necessary it will be pretty easy to shape the beam. 

[jmengel]

If you plan on building, I'd say wait a bit until I get the latest instructions ready as the latest light design is much improved.

[fabelizer]

Very nice! Great job on the instructable. Where did you get your LED and lens? Any info on length of run on a given battery? -fab

[jmengel]

See Step 1.

Run time depends on a lot of factors, for rough guess divide battery WattHrs by LED wattage. For example, 12V 2Ah= 24 Wh and 2.4hours runtime at 10W.

[frenzy]

i bought a 4.5 watt high powered light from a cataloge, and this seems MUCH more powerful. thanks for doing it.

what did you use for a battery?

combine with my project and get awesome:
http://www.instructables.com/id/Putting_A_Car_Horn_On_Your_Bicycle/

[jmengel]

Nice horn. I've had a few opportunities where a horn could have been helpful. Well tuned front brakes seem to be the best solution usually. As I mentioned in some other reply, I have a number of different batteries that have been used to power my bike lights (and maybe horn in the future). The original is a 12V 7Ah battery that is heavy but fits a bottle cage nicely. The newest solution is a 12V Li-Po-Fe pack, which has only 1350mAh but is so light (only 4 cells) that it is worth the trade. I got them both (and others) at Batteryspace.com. Great site.

[XilStorm]

lol. if you're riding with other people, you could scare them off their bikes. Just don't do it in traffic =)

[JonathanPeterson]

I don't know that a spot lens is really preferable. One of the big problems with led bike lights is that they don't have as much scatter as halogen bulbs, so you aren't as visible to drivers on side streets. If you're throwing that much light out there, drivers are going to know there is something out there - even if it might be a low flying plane.