Bright Rechargable Headlight for Your Bike!

 Bike headlights generally fall into one of two classes. To see, or to be seen. My mountianbike group cares a lot more about seeing since we tend to ride in places where hazards like cars do not and cannot go.
Here's what we came up with. 10 watts (between 150-200 lumens is our guess), $34.00 including light, battery pack and charger. Using disposable batteries can bring this project into the sub $15.00 range real quick.
The light burns bright. It's completely waterproof and the PVC holds up to the heat the lamp produces without issue.

Step 1 Materials & Tools

Before we begin
We believe in making use of available materials. If you have something laying around that you think will work as a suitable substitute for any of these materials, by all means, use that instead. Beyond that, the 1¼" compression fitting found at my Home Depot may not be the same as the one at your Home Depot. When we ran the workshop, we ran in to this very issue. This is a very versitile project. Here are some examples of the many variations that could be done to this project.

• The enclosure could be made more compact if you glue it together so when the lamp eventually burns out, you just throw it away and build a new one. This part of the project would be about $5.00 if built this way.
• Omit the switch. You can have it so you plug it in to turn it on. By doing this, the whole thing could fit into the 1" pipe cap.
• Build it in to something you already have.
• Make it brighter! 20, 30 and 40 watt lamps are available. Just remember, the brighter the lamp, the more battery power it will take to deliver a useable burn time. Something as bright as a car doesn't do much good if it only lasts 5 minutes.

The possibilities are endless. That said, here's the variation we built. We had a workshop where we built 26 units at a cost of $34.00 each including light, battery pack and charger.

Materials (per unit)
1ea. - 10 watt, 6 volt, Halogen Lamp with MR 13 base
1ea. - 2 pin screw terminal to connect to the back of the lamp
1ea. - Waterproof pushbutton switch (push-on, push-off)
1ea. - 2.5 mm Male coaxial power connector with cord. (Power wire)
1ea. - 2.5 mm Female coaxial power connector
1ea. - 7.5 volt dc wall charger with 2.5mm Male coaxial power connector (omit if using alkyline batteries)
1ea. - 8" piece of zip cord (AKA speaker wire, lamp cord etc.) It should be at least as heavy as the wire on your wall charger.
1ea. - 1" PVC pipe cap
1ea. - 1¼" ABS compression fitting
1ea. - PVC solvent cement
5ea. - Nickle Metal Hydride (NiMH) Recharable Batteries. Size "4/3 AA"
OR
1ea. - 4 cell alkyline battery holder for "AA", "C" or "D" cells

Tools
Safety Glasses
Hacksaw
Hot Glue Gun
Vice
Soldering iron or gun
Volt Meter
Pliers
Screwdriver (small flat)
Sandpaper
Drill & bits

Comments

[mwhitt]

If you solderup the switch first, you only have its 2 wires in the way when installing the switch in the end cap. Making the tightening of the nut easier. IHTH, Matt W.

[zoltzerino]

 I would REALLY appreciate it if you could post an image of you using it in a pitch black room (for example), just to give me an idea of how bright it is.

Really nice project; I will build it some time.

[evogav]

That was probably the best instructable that i have ever seen. Thankyou very much - nice easy project. Very educational too for those who need it (myself included). This would make a great addition to my motored mountain bike (67cc Grubee engine). I just need to learn how to use my 6-8v ac output of this engine to keep tthe batt pack charged up.

[shrpshtr325]

awesome idea, i am thinking about making one with a bunch of LEDs that i have around (hoping to end up with 2 5 led units for my handlebars) and some old rechargables in a seperate housing so i dont need to buy a seperate charger the only part i havnt been able to find something for is the reflector and lense, any suggestions? Im not above making one myself

and one other question, how did you calculate the current/voltage you needed for the charger??

[Marsh]

The reflector has kept me away from using LEDs at all. All I can think of is old flashlights or other types of lamps.
As far as the charger goes, I just guessed. I've been working with this kind of thing for many years so I knew a 7.5 vdc charger would charge a 6 volt battery just fine. That, plus they were on sale for $2.99.

[shrpshtr325]

ok, thanks i was thinking of running the 2 5 led lamps each led at .02 amps a pice (20mA) and im planning 4 stacks of 3 1.2V 1000mAH batteries equaling 4 aHs and .02*10=.2
4/.2 = 20, i have a feeling that is a very optimistic rating in hours for battery life, but i will see

and i guess im going to make a trip to the dollar store to see what kind of flashlights i can find to make work, lucky me, i will update when i get it finished, maybe even some pics

[Marsh]

 Take pix of the whole process. That's how Instructables begin. There's a contest for lighting right now too.

[tygish]

(removed by author or community request)

[Marsh]

 Have a look at step 9 for complete details on how to compute this value using the batteries you buy. As built, 2½ hours.

[neivadan]

try car battary insted that should make it last longer and ment by longer i ment way longer.

[TURNERO]

Have you tried it with one of the LED MR-16 bulbs? Surely that would make it last longer and be much more durable. Unfortunately they cost about $30.

[neivadan]

ah did u just say 30 bucks can't u just pust those swirly ones that way the lighting will be bright and its inexpensive.

[Marsh]

 Cost was a big factor. Speaking of big, the MR-16 is no small-fry either. The home made enclosures we came up with for MR-16s were really bulky. People didn't like them. Thanks for looking.

[TURNERO]

My bad, I didn't notice the fact that it used MR-12 bulbs.

I found these LED MR-11 bulbs for $15 each. Not sure how bright they will be though:
http://superbrightleds.com/specs/MR11-WHP6.htm

Good instructable BTW, given the price of decent bike lights I like that there are options like this.

[neivadan]

man thats alot of steps but aleast tis worth it

[Chromatica]

Nice