Triple SSC P4 Light
Hi everyone! I've been promising some beamshots to compare these LED bike lights (that you can build from the instructions on this web site) to an HID light. I finally got around to borrowing my friend Gina's L&M HID light and went into the backyard and took some comparison shots. I don't need to say too much other than all shots were at the exact same manual camera setting (F2.8, 1/4 sec, ISO 200). The camera was on a tripod to give the exact same view for each shot, and I tried to aim the hotspot of each light in the same location.
I tested all lights on freshly charged batteries, and I let the HID warm up for about two minutes before taking the photos. The Light & Motion ARC HID draws 13.5 watts on its high power setting and 11.5 watts on low. The upper left and upper right photos represent those two settings for the L&M. It's a nice lighting system. Gina's light is a couple of years old but still looks pretty bright. The lower left photo is one of my Triple SSC P4 all-aluminum lights like the one shown below, execpt that it has a 5 degree reflector on the middle LED and 2 x15 degree optics on each of the other two. The lower right photo is my Triple SSC P4 Copperhead light shown below with 2 x15 degree optics and 1 x 5 degree optic. The L&M does have a wider light beam than my LED lights as you can see from the larger lighted area of grass. But all in all, I think the DIY LED lights hold up fairly well against the L&M HID especially when you consider the power consumption figures into the comparison.
Below are the Triple SSC (Seoul Semiconductor) P4 (all aluminum housing) and the Copperhead (aluminum-copper hybrid) lights. Within this site you will find step by step instructions (with many photos) for building either light.
Triple SSC P4 (U bin) with L2 Optics
The Triple,
All-aluminum housing (above) is a refinement of my original square tube
light design. Each time I build a light I learn a thing or two. So far
I've built a dozen or so of these. Some for me, some for friends, and a
few to sell since quite a few folks seemed interested in that. It seems
that I can't even make minimum wage for my time spent
building them, so I will not be building anymore to sell once the few I
have are gone... sorry. But really, it's more fun to make the light
yourself anyway! I certainly don't mind answering your questions!
The Copperhead
The Copperhead, shown above, is the most recent light that I've built. I was wanting to do something with the copper end caps and I'd seen several variations on lights using them. It was a fun project, and the light definitely has the "steampunk" look! This design is also a little easier to build than the all-aluminum square tube housing, but it weighs about 35-40g more than the all-aluminum light. (130g vs 170g). Some folks have pointed out the potential for corrosion between the aluminum and copper components, but in this particular build the pieces are actually separated with some Arctic Alumina Adhesive, which physically isolates the two metals. I have not noticed any apparent corrosion after several months. The biggest drawback to the Copperhead is that I do notice it a little more when wearing it on my helmet... but it's not a real show-stopper. It's probably lighter than some of the commercially available "helmet mount" lights.
Where do LED bike lights stand in terms of brightness compared to HIDs and Halogen?
I guess this question is better answered now that I have posted the beamshot comparisons at the top of this page (although I apologize that I don't currently have a halogen light to compare). When I first started this site, a couple of years ago, I was comparing LED bike lights to halogen-based systems, and now I'm comparing them to much brighter and more efficient HID systems! The light shown below is my triple SSC P4 (U bin). I ride with many riders who own L&M (Light & Motion) HID lights (a great system by the way) and I would not trade my homebuilt light for one of theirs. Why not, you ask? Well, I can turn it on and have it at full brightness, instantly... HIDs, which are arc lamps, must ramp up to full brightness and that takes nearly a minute. Also, I can instantly adjust the brightness of my light to whatever level I choose. It's certainly nice to be able to dim (or completely turn off) the light when riders stop at the trail heads waiting on others (it's not good for HIDs to be turned on and off frequently). When you don't need as much light, dimming the light also extends battery life. Speaking of battery life, a triple LED light running at 11.8W is about the same brightness as the L&M HID running at 13.5W... so the LED light will have better battery life... it is more efficient. Another cool thing, is that I can change out optical lenses pretty easily if so desired. Although I'm real happy with my current lens configuration, various lenses can be mixed and matched on the 3 LEDs to offer different types of beam patterns to best suit my needs.
Shown below is a photo of one of my triple SSC P4 lights with dimmable 3021 buckpuck driver and L2 optics mounted onto my trail riding helmet.
Triple SSC on my helmet
I started building LED bike lights in 2005 and have had good success with them. My main purpose for building these lights was nighttime mountain bike riding... and I like to tinker with things. During the winter months, the daylight hours are just too short to find time to ride during the work week, so many of us have taken to riding the trails at night. Many of my fellow riders have nice, bright HID lights that they forked out big bucks ($400+) for. I had a hard time justifying spending that much on a light, so I started out with some home built halogens back in 2003. The halogens worked okay, and offered a good lumens per watt value for bike lighting, but then I discovered the new (at that time) superbright Luxeon LEDs and began to consider their use in bike lighting. Once I built my first triple Luxeon III LED light, the halogens were tossed out for good! Luxeon LEDs are currently being outperformed by the Cree and SSC LEDs, but there's a good chance they'll be back in the race eventually.
Cree XR-E on a Star
- More
lumens per watt.
(I didn't say more lumens per dollar... but we're getting there!) I
consider about 10 watts as the most drain that I want on my battery
pack because I want it to last as long as possible and I do not want to
carry around a huge battery pack. A 12 volt, 10 watt halogen MR11 lamp
puts out around 190 lumens
whereas a 12 volt, 9 watt Luxeon bike light (3 x Luxeon III, 3 watt
emitters) puts out about 240 lumens. Recent technology with the Cree
XLamp XR-E emitters will double that output number with even
less
current draw from the battery. The XR-E is said to offer 160 lumens of
output at 700 mA. So a bike light containing 3 XR-Es should output 480
lumens, drawing 700mA at 12 volts, or about 8.4 watts. That's 57
lumens/watt... not too bad! Cree recently announced that they will be
offering LEDs with 80 lumens/watt by late 2007. Can you
imagine a
9 watt bike light that puts out more than 700 lumens? So by the end of
2007, LEDs will have even overtaken HIDs in terms of lumens/watt. [Edit
11/25/2007, I've left my original text above, and guess what?
We're there! It's actually more like 700 lumens at 11 watts though]
- Abilty
to configure
beam pattern with various optics and reflectors. You can
buy a
few different beam configurations of halogen lamps, but the availablity
of optics and reflectors for Luxeons and Crees are quite good, and the
ability to mix these within a single, multi-LED bike light makes for a
really customizable beam that meets your riding needs.
- Lighter
weight -
of course this depends on the construction of your light, but the
emitters themselves are very lightweight and don't require a big
ceramic socket to plug into. Some lightweight aluminum will do fine for
mounting the LEDs and dissopating their heat.
- Longer
run time
(less current drain on battery for equivalent amount of light) -
absolutely. You would have to nearly double the halogen watts to get
the same amout of light as a modern LED bike light. For example: a
triple Cree XR-E light = 480 lumens @ 8.4 watts while a
halogen
MR11 = 400 lumens @ 20 watts). [Edit
11/25/2007, a 3x Cree XR-E (Q5 bin) light = approx 700 lumens @ 11
watts]
- Better,
whiter (less
yellow) light - the color of light is really a subjective
matter. But to most people, the whiter light of an LED will be more
pleasing and will also be perceived as more light output even with less
actual lumens of output.
- Less heat - while the LEDs do generate heat and require heat management as a consideration, the halogens get much hotter. I could always smell mine burning the paint (or something) off of the lamp housing... even in cool weather. The aluminum cased LED lights that I've built barely even get warm to the touch while bike riding.
- Longer life/less prone to failure
This is a hot area of debate on many bike lighting related forums. I personally don't have anything againt HID lights and often recommend them to people who are looking to purchase a very bright manufactured bike lighting system. But as I mentioned earlier, I feel that the latest generation of LEDs offer the ability to have an LED bike light that is just as bright as an HID light and is more flexible and power efficient.
Building your own light offers even more flexibility. You can choose the number of LEDs (typically 2 or 3) and the type of optics to determine what type of beam you will have emitting from your light. Building these lights is rewarding and for some even addicting! No really, I can stop anytime... "my name is Allen, and I built my last bike light over two months ago... OK, OK, I modified one last week."
A stack of finished and partially finished LED bike lights.
It's fairly simple to construct your own LED bike light if you have basic electronics knowledge, some soldering skills, and some propensity toward being able to errr... construct things. I will try to arm you with the basic knowledge, tools and techniques needed and set you on your way to DIY LED light construction! But first, the usual disclaimer: "I will not be held responsible for any damage to yourself, your personal property, or anything else for that matter, as a result of using the information contained within this web site." Now that that's out of the way, let's get started.
LED bike light construction can be broken down into the following areas:
- Building the all-aluminum square tube light housing (detailed instructions with photos) and a means for mounting on the bike/helmet. This is typically the most difficult area in bike light construction.
- Building
the Copperhead Bike Light (detailed instructions &
photos)
- Electronics and LED selection - this will cover both the LED choices and the required circuitry to drive them.
- Optical considerations: In my earlier days of bike light construction I was convinced that using reflectors was the way to go. LED flashlight experts said that they were more efficient and offered more throw. This information is probably true, however as I continued to experiment, I discovered that I liked the flexibility of being able to choose from quite a few different optical lenses that were available. I discovered that by mixing different optical beams in my triple LED light that I could achieve just the right beam pattern for my riding style. For trail riding I like the combination of 2 x 15 degree and 1 x 5 degree lens (in a triple LED light). There's no reason you can't mix reflectors and lenses. I have one light that has two 15 degree optical lenses and one 5 degree reflector. Most lenses are only about 90% efficent, meaning you will loose about 10% of your total lumen output in the lenses, while many reflectors are said to be a little more efficient. So when calculating your actual lumen output from a light, you must subtract for the loss introduced by the lens or reflector. So if the lumen output from your 3 LED totals up to about 720 lumens, you'll have to subtract about 72 lumens that are lost in the lens, resulting in only around 650 lumens output. So why use optics at all? You must control where the light is concentrated in order to make the light beam usable...
- Thermal management - we must keep our LEDs from frying. LEDs can get hot! You should never apply power to your LED without it being thermally attached to something that will wick the heat away. Thermal management is important, and is basically why most LED bike lights are constructed from aluminum... it is pretty good at dissipating heat away from the LEDs. My earlier LED bike light designs incorporated heatsink fins similar to what you might see on your computer's CPU chip. It seems that I remember reading somewhere that about 3 square inches of exposed heatsink area per LED watt is a general guideline for heat dissipation. So if our total LED light wattage is 11 watts, we should have about 33 square inches of exposed aluminum to dissipate the proper amount of heat away from the LEDs. My triple LED light design has a total of 17 square inches of exposed aluminum surface, all of which is thermally connected to the LEDs.... woefully inadequate until you take the airflow provided by the moving bicycle. Operating my light without air moving across it will result in an overheat condition! I will expand the TM section more later, because it is important. Nearly all major LED manufacturers have PDF documents available that offer excellent TM guidelines and advice... I recommend that you read them!
- Installation of the LEDs, electronics, and power connectors (photo guide for a Triple Cree)
- Battery considerations - we could have put this within the electronics section, but since it's external to the light itself, we'll discuss batteries separately. Most high power LEDs require about 3.7 volts at 1A to power them (it varies from LED to LED). With 3 LEDs wired in series (the recommened way), that's a total of around 11.1 volts. Using a buckpuck style driver consumes about another volt, so a total required voltage for a 3 LED system is just over 12 volts, minimum. You might get buy with a 12 volt battery, since when fully charged, many are 13.8 volts, but as they drain down you will probably notice some dimming of your light (a 12v will work fine if you're building a dual LED light). A 14.4 volt Ni-Mh (Nickel Metal Hydride) or a 14.8 volt Li-Ion (Lithium Ion) rechargble are the recommended batteries for this triple LED light. Since the voltage is higher than required, the current draw will only be about 0.75 Amps. As the battery voltage gets lower, the current draw will increase.
The main parts of my all aluminum triple LED light housing.
SSC P4 on a Star MCPCB
Parts/Source List
Many people have requested this. It is a little difficult to put a parts/sourse list together, because (1) I build variations on the light and (2) my sources change from time to time. Anyway, here is a typical parts list of a Triple Cree XR-E light that I have built. I do not endorse any of the sources below, but they are just some that I have used. I'll try to recommend multiple sources where applicable. I spent about $110 (US) building the Triple Cree. You can probably do it for a good deal less now.
Another thing people ask: "is there one place I can get all of the stuff from to save on shipping?" And the answer is "no." Cutter Electronics might be the closest thing to that, but they are in Austrailia, their prices are a little higher, and it takes a while to get stuff from them (just my opinion).
- 3 XR-E (P3 bin) + 3 Ledil optics + S&H = 62.11 Cutter Electronics in Austrailia , DealExtreme.Com
- Dealextreme is cheaper and faster than Cutter, but you'll have to get lenses elsewhere.
- So, another source for optics is Led-spot.com, but you have to email or call them to order. I have not used them yet, but I've heard from others that they are friendly and that their prices and S&H are reasonable.
- 1 nFlex controller + S&H = 30.18 TaskLED
- the bFlex controller is probably the one to use these days... was not available when I ordered nFlex.
- 1 momentary contact switch = 2.65 RadioShack
- 1 size M, DC power connector = 2.15 RadioShack
- 1 foot of 1" (1/16" thickness) square aluminum tube = 4.50 (Lowe's hardware dept) - I think I had to buy a 4 foot section
- J-B Weld (used less than 1/10) = 6.00/10 = 0.60 (Walmart or auto parts store)
- Arctic Alumina Adhesive (used about 1/3) = 7.00/4 = 2.35 Sandwich shoppe, CoolerGuys
- Wire (24 ga), and solder = 2.00 (Radio Shack)
- 2 #8-32 hex head screws + washers + rubber washers = 2.00 (Lowes, Home Depot, or Ace Hardware)
- Rubber grip for bottom of helmet feet = 1.50 (Walmart, Lowes, Home Depot, or Ace Hardware)
- 1/16" thick plexiglass - Local hardware store (Lowes, Home Depot, or Ace Hardware)
- Clear silicone caulking - $2.00 - Local hardware store or Walmart.
- 3 Seoul P4 LEDs (U-bin) DealExtreme (sells on a star MCPCB) , Sandwich Shoppe (sells bare emitters)
- Recommended optics for use with Seoul - 20mm L2 (2x15 degree, 1x5 degree) from LedSupply
- Roadies always want more spot light than off-road mountain bikers, so consider 2x5 and 1x15
- Don't forget holders for the optics: (Luxon III or Star Optic Holder)
- 3021 or 3023 (wired) Buckpuck LED Driver from LedSupply
- You can save a few dollars by using a simple 3021 or 3023 wired Buckpuck (about $20 + S&H) as opposed to the bFlex. The only deal is that you have to choose the drive current you will be using. 1000mA works well for Seoul P4 or Cree XR-E as long as you are able to keep the lights cool (keep pedalling man!). In some ways I actually the prefer the simplicity of the 3021/3023 buckpuck over the bFlex, but it really depends on what you're looking for.
I use 14.8V, 4A Li-Ion packs. A battery pack and charger will run you around $85 - $95. I've bought from the following two sources without problems:
BatterySpace
All-Battery
Some people on MTBR.com have complained about BatterySpace.com, but I've never had any problems with them.
Dual Luxeon V Light
Here's my MTBR Thread on the Dual Lux V light.
Triple Luxeon III (TVIJ bin) Light
Here's my MTBR Thread on the TriLuxIII light.
Triple Cree XR-E (P3 bin) Light
Here's my MTBR Thread on the Triple Cree XR-E light.
Triple Seoul Semiconductor P4 (U-bin)
Here's my MTBR Thread on the Seoul P4 light.
MTBR.com bike lighting specific discussion forum - many great contributors
Candlepower.com bike light specific forum - the original source for many LED flashlight tech discussions and they now have a bike light specific forum.
I had a few of these light systems that I'd built to sell. It turned out to be a very non-profitable venture considering the time and effort involved in putting it all together, but at least a few lucky people got a good deal on a light system with Li-Ion pack and charger. I will not be building any more to sell, so please don't ask :)
1 - Helmet mount 3xSSC P4 (u-bin) LED light w/aluminum housing, (2x15 degree, 1x5 degree) L2 optical lenses, Buckpuck 3021, 1 Amp controller with continuous dimming control. Includes 2 Velcro fasteners for attaching to helmet (red ones in this photo). The light has a very smooth beam that is perfect for trail riding, IMHO. This is designed for light on helmet and battery in backpack/camelback.
1 - 14.8v, 4A Li-Ion rechargeable battery (built-in overcharge/short/low voltage) protection
1 - 14.8v Li-Ion battery universal smart charger.
Battery and charger are brand new in box, and the light has one test ride on it.
.
Light output: 3xSSC P4 (U-bin) = 600 to 780 lumens (based on mfg ratings) or about 660 typical lumens on average. Now subtract about 10% for loss in the optics, and you get about 595 lumens as a typical output coming out of the front of these lights... not bad :)
Runtime: about 4 hours of bright light on a charge (at max brightness level)
Dimmable: the light is dimmable via an easily reachable knob on rear of light. Dim it down a little as a courtesy to fellow riders when talking at the trailhead, or lower the ouput to extend battery life.
Weight: 130g (light), 600g (battery)
Yes I do other things besides ride bikes, build bike lights and maintain this web site...
Me playing guitar ... video on youtube. Here I'm playing my Godin ACS guitar with Roland GR-33/GR-20 synthesizers. The song is a Pat Metheny song called "Close to Home." (head chopped off and no bike light in picture :)
I like sailing too. Here's a photo of me sailing on my boat. Forgive me, it was a lazy day and I was only using the gib and didn't bother to raise the main sail.
Email me if you have any comments or questions.
Regards,
- Allen Chapman