Can You Help Me Start My Bike Light Project please?

The Background
I mainly cycle in London so along lit roads & generally only need a 'be seen' light & that's what I had for the most part - some form of Cateye LED light. Riding home one night I took the canal route - faster becuase of no traffic lights. Cruising at about 20mph, I suddenly found my wheel had found a crack in the towpath & was guiding me to the water. I tried to lift the wheel & steer out but it was like I was on rails. With 4kg of locks on my back, I didn't fancy my chances in the water, so I took a drop to the landside. Not a great experience so Idecided i need more light for my canal shorcuts.

The Solution
Brighter Lights so I can see where I'm going. Thing is nothing really offes what I'm after so I decided I want to make my own. Found loads of links on homemade halogen systems but with a typical journey of 2.5 hours , I don't fancy the battery weight. LED seems like a great solution!

My main Inspirations during the six hours I've been online researching are Nightrider's Dual Luxeon V light & Electrolumens Quadstar Bikelight

My Problem
I don't really understand the electrical side of things. I've tried researching things but I just don't get it & was hoping some of you might help.

So far I am planning to run 6 1.2 volt 35003mAh in series to give me 7.2 volts like the Quadstar. I want to run two 3w luxeons (in series?) - is it just a matter of connecting the to the battery or will this method risk damaging the LEDs?

If I can't hook up directly to the battery do I need to run one these things?
Konlux Constant Power 350mA / 700mA / 1000mA / 1050mA / 1400mA

If I do need one, which one? I'm guessing it's a shootout between 700, 1000 / 1050(?) & I guess with 1000 I'll get more light than 700 but then I thinkg the LEDs draw more current so would I need another C cell to bring me upto 8.4 volts?

Also, do I need to place a fuse close the battery & if so what rating?

I really have no idea on this part & want to be as clear as I can before I place my orders so that I can order all my parts in one sitting & hopefully have them all arrive at more or less the same time.

I know it's a bit long winded & perhaps blining simple to those that know so thanks for your patience

this konlux thing is quite nice

ok first thing, the amount of volts you need greatly depend on your led's bin as it may be
more then 8.4v if running in series.

i would suggest you run the led in parallel and buy the 1400ma thingy, so that each led will get 700ma. i believe they said the thingy will provide the luxeon what voltage they need, so you won't need to worry about that

Welcome to CPF ixus.

Have you considered using a high quality led flashlight head, i.e. Surefire KL4/KL5, or a less expensive light such as the Nuwai ALX series 5 watt lights?

I'm an avid cyclist and have been expermenting with custom bicycle lights for the last ten years. My problem is always battery weight to run time. I usually run a light that is much brighter than necessary, 20 watt Halogen flood and a 20 watt Halogen spot.

As for a 'be seen light' and one that should light the contour of the road surface for safe at speed riding, I was thinking a Surefire KL4 or a KL5 head might be just the ticket. All you would need is a decent clamp for the handlebars and some rechargable Lithium Ion batteries.

Now for 2.5 hours of uninterupted light???

would recommend buying a light from a bike light mfg.
major problem of fab'ing a decent handlebar mount

best light mount for mounting a std flashlight is Two fish cycloblocks.

I run Surefire U2 with 18650 li-ion for aprox 2 hours runtime on high. runtime is much longer, because I'll run one step down. carry two spare cells and you've got lots of runtime.

primary light is Niterider Storm HID for 4 hours of runtime.

if you've already got lots of light, go with twofish VS if you have to purchase a light like U2, might as well buy a bike light from a bike mfg and be done.

The handlebar config. in your photo cy, tells me that's a recumbent?

Sorry ixus, I'll stay on topic here forward.

The idea of using existing led lights is great because you don't have to know anything about the electronics, more or less. Plus, if you use a Surefire product, weather proof and durability are already built in.

I use a Fenix L1P mounted on my helmet to be seen but not to see with. To make a "real" bike LED light requires several hundred lumens if you want to ride at 20MPH safely. My plan is a frame-mounted (recumbent) bike light using Andrew Wynn's BAM 4 LuxeonIII emitter Mag drop-in mod with three light levels. 700mA (400+ lumens) 350mA (240 lumens) and 70mA (60 ?? lumens) These levels are at the LED and are assuming S bin Luxeon K2 LEDs (not released yet but pending)

Luckily, street riding requires less light than mountain bike riding so 400 lumens should be fine. It might be April/May before the BAM SWAH K2 Mags roll out but I can wait.

sounds like regular use, so consider only rechargeable lights.

btw. have this endless discussion here also and my personal thinking is: on a bike-for-regular-street-commuting (NOT my MTB) the only way to do is dynamo (working when needed, no matter if cared for or not)

+ "we" just finished a mod of an exisiting 12 V Spot featuring buck circuit and a Lux III Led. Working good so far
http://nyx.at/bikeboard/Board/showthread.php?t=43146 (my tread on another forum, the idea was stolen somewhere else)

I use a pair of MXDL flashlights and am extremely pleased. You can find my setup here.

The handlebar mounts were really lousy so I picked up some mounts that permanently attach with no quick release clamp. I'm quite pleased with them.

To improve runtime, I purchased three LaCrosse BC-900 chargers, cycled and tested all of my batteries, and put together a bunch of matched battery packs. That made a big difference. If I needed more runtime, I'd go for higher end batteries than the generic green chinese NiMH cells I'm using now. For my purposes however, my current batteries are perfect.

The next step is going to be to mod a pair of MXDL lights with a 5w Luxeon and Fatman driver in each light. I'll remove the tailcap switches and use the hole in the tail cap for a connector to an external pack. Then I'll be able to run a 12 cell pack and have crazy runtime, better brightness, and easy charging with a multi-cell smart charger. It should be fairly simple and pretty sweet.

In the mean time, I'm totally happy with what I have in the pair of $10 lights. They really throw light, as I hope you can tell in the pictures I linked to above.

Please keep us posted as to how you make out. I've gotten a ton of great ideas from these forums and it's always great to see what other people are doing.

TranquillityBase said:

The handlebar config. in your photo cy, tells me that's a recumbent?[.

Click to expand...

yup, it's a Lightning P-38, it's bentheadtx's fault

here's pic with HID mounted

I'm very interested in your story (all things Bent) cy, but don't wish to corrupt ixus's thread. I started a new thread in the CAFE

http://www.candlepowerforums.com/vb/showthread.php?goto=newpost&t=103501

TB

If you are going to make it your self, try making it like nightriders. Only i would use the fatman or nFlex boards from taskled.com. you can find nice lightweight Li-on battery packs from batteryspace.com. Those should help with your light output to weight issue.

Brian B.

I've been combining a Pila GL3 and a SF U2 for my short ride home. Based on CY's reccomendations, I also use twofish lockblocks.

Wow so many replies so fast!

I have considered using a torch & indeed torch head but ultimately I quite like the idea of making my own head & having something quite small. I really like the idea of using square aluminium tubing or some sort of halogen holder - I've seen a nice nikel plated one intended for undwerwater pond use which has the advantage of being waterproof (here).

Making the battery pack loooks easier than I imagined. I was going to use something out of a readio controled car with siubtable smart charger but found it's cheaper to ake my own. I found cheap batteries from a UK site here & they are rated quite high in power terms. Battery weight is not too much of a problem - I figure something that can fit in my unused saddlebag would be fine - I plan to mount he saddlebag around the handlebars like Electrolumens has done in his Quadstar pictures, so as to keep cable length to a minimum.

I'm not too worried about being seen when it comes to this bike. Generally I ride in well lit streets & a cheap £5 LED front flasher should fill me needs in this department & have the added advantage of being a backup / failsafe.

I only plan to use the light on the darker secrions of road like when I cycle out of town, or even circuits of a nearby park or most importantly the canal as I dont want to end up at the bottom of it.

I'm not sure what beam pattern I need - obviously something with a bit of throw but also enough side spill so I can see where the water is & have soem periferal vision. Riding slower isn't really much of an option - I am riding a fixed gear bike (42x16) and find 20mph to be an efficient speed for me - any slower & am mashing the pedals more & tiring quicker

I still dont understand the drive thing though. A couple of you have suggested 700mA but why not 1000 or 1050? Surely that would be brighter?

I have no idea what LED bin is? This is where I'll probably buy my Luxeon 3s but I can see any bin info
dotlight.de

I'll probably buy the power regualter board from there too if I need one - do I?

I looked at the fatman link but buying from the US takse to long in shipping & plus I hate the tax lottery when mail order stuff arrives at my door. For supplies I'll be sticking to UK / Eu sites as it's just quicker & easier

Yes, you'll need a driver.
It doesn't look like that Konlux driver will fit inside the 1" square aluminum tubing.
There is much info on both "boost" and "buck" type constant current regulators here on CPF, just do a little more research and learn more than I can explain here. Figure out what you need before you buy. You could build your system around a particular driver, but that will dictate the batteries and LEDs you use. Remember that it all must work together as a system. I like the 3021 or 3023 (wired version - easier to deal with, but no dimming) Buckpuck because it accepts a wide input voltage range, it potted (waterproof), and is small. If you were to run with less battery voltage than your LEDs require, you would need a "boost" type of driver/regulator. More info: http://www.ledsupply.com/led-drivers.html

Three Lux IIIs provide a good deal of light. Recommend wiring in series so all LEDs recieve same current and using a 1A driver. You'll probably need at least a 12v battery pack though... maybe more depending upon LED bin.

Bins are ratings for Lumen output, color, and voltage min/max. Do a search on Luxeon bins. You'll find the info.

Riding at 20 mph you'll want some light shining down the road a ways, so I'd recommend the 20mm reflectors. I ride only on trails at night, at around 10mph avg. The combo of 3xLuxIII on my helmet and 2xLuxVs on the handlebars is awesome! The Lux Vs provide more flood to light the ground in front of my bike, and the LuxIIIs shine a powerful beam wherever I look. BTW, I'm running a 4A, 14.8v Li-Ion battery now... it is lightweight and provides a 4+ hour runtime.

Good luck. You'll get tons of great info here on CPF.

My apologies for taking so long to reply - I've been having problems with the candlepower forums & they were seeming to choke my webbrowser (firefox on a 366mhz G3 iBook running osX) Seems too be running a bit better now since teh upgrade to Firefox 1.5 though (fingers crossed)

Thanks for the tips nightrider

On your advice I have decided to purchase the buckpuck running at 1000mA & I am going to power 3 luxeon IIIs from it runnign in series.

For power I have ditched the idea of the 3500 C-cells becuase of cost (£50ish) & weight decided to with 12 2200mA AA batteries although I would have prefered 25's there is a huge price jump so 22's are teh best I can budget for at a cost of £35.16. I figure this should give me just over 2 hours which should do me if my calculations are correct. Please correct if this is wrong:

==============================================

12 2200mA batteries at 1.2 volts gives me:
14.4v x 2.2Ah = 31.68W.hours of energy...
assuming the T bin Lux's draw 3.9v...
31.68 / (3.9 x 3) = 2.71 hours
I assume (from bits I've read elsewhere) that the circuit is only 85% efficient...
(2.71 / 100) x 85 = 2.3 hours run time (correct??)

==============================================

I'm getting a smart charger for less than £20 & it comes with a range of fittings. I might use either the radio controlled car type or make up a DC to DC lead wth 2.1 or 2.5mm plugs to connect battery pack & light housing.

Fingers crossed that I may have come up with an ideal housing for the lights in the form of an aluminium 'stash' tin. Sealed aluminium even with a runner O-ring. Not sure if it's wide enough for me yet - waiting on a reply from the suppliers.

I still have a few questions:

Do I need to add an inline fuse close to the battery, like you would with a 12v car system & if so what rating should it be?
&
Do any other bikers have lens recomendations? I can seem to find any of 20mm type - onlynarrow 6degree 10degree, wide, eliptical etc

should I go for 2 narrow, one wide? How wide? I could do with side vision & need to be able to see quite close infront of my wheel since it was a crack in concrete that almost landed me at the bottom of a canal

thanks again

1000 and over will be brighter, but the increase in brightness greatly outweighs the significant decrease in runtime

Brightness is the key

As long as I have over 2 hours I'll be happy. I love the idea of separate battery pack as I'm sure even smaller, higher capacity batteries in a couple of years time so as long as my light is bright enough to begin with, I should be on to a keeper.

I'm no expert on batteries but I'm pretty sure they have made huge advances in the last few years & I expect more to follow

On a side note, buck pucks are sold out till the 16th

This is bad news, not just becuase I have to wait but becuase by then I shall be back at work

... inexpensive 2500mah NiMh .....
i`ve used em for a good while with excellent results

http://www.7dayshop.com/catalog/default.php?cat=3&type=3060&man=96&filterwords=&go=SEARCH&comp=

Halfords (a UK vehicle chain store) has a new range of own-brand LED bike front lights made by Hella.

They use a 1W Luxeon with an excellent collimator made especially to produce a cycling type beam which is also BS-approved (AFAIK).

I bought one for a friend of mine for Christmas and she is pleased with it - having previously used 2.4W Cateye lights.

Having made several of my own LED bike lights, and spent several hundred pound doing it, I would say buy a couple of these and try them.

If you don't like what they do, use them as a base for a higher-powered system. They have the optics and LEDs. All they lack is a better heatsink and power source - and maybe conversion to 3W Luxeons.

Be aware that a lot of LED optics have circular beams and as such put a lot of light above the horizontal - fine for being seen by, but tough on cyclist and pedestrians trying to use the canal tow path in the opposite direction!

Steve (in Surrey, UK).

Wow!!

Thanks a lot Hendo You saved me over £10. Just in time too - I was just about to order batteries from budgetbatteries.com but have now run into a problem with their 3.8-14v charger - it can only charge a max of 12v -wtf?? I don't understand where they get the 14v figure from then.

Anyway that's another set back. I'm trying to find another charger or if not I might just have to buy that charger & charge up 2x7.2 volt battery packs then connect them some how in series for the light :/

HEY HEY ITS HENDO said:

... inexpensive 2500mah NiMh .....
i`ve used em for a good while with excellent results

http://www.7dayshop.com/catalog/default.php?cat=3&type=3060&man=96&filterwords=&go=SEARCH&comp=

Click to expand...