LED Headlight

[chimichanga]

well I made an led bicycle headlight. I used one 10 mm white LED and a 5 mm white led. They are hooked up to the switch which is also hooked up to a twoo AA battery holder. When I put in the batteries within 30 second my batteries get hot and smoke starts coming out and the led's arent even on. Eventually the batteries die. I know i did something wrong. Any help would greatly be appreciated.

 

[ifitsfreeitsforme]

yikes!

i'm planning on converting my old headlight to LED but I'm taking the cheesy way out and doing this:

http://www.howtofixbikes.ca/2007/02/how ... cycle.html

 

[socal_jack]

You can't hook the LEDs straight up to the battery like that, you'll need a series resistor to limit the current. See the following link for calculating what you need, if the LED came in some packaging it should tell you the "on" current and voltage which you can plug into the calaculator on the page. Just follow the hookup diagram.

EDIT: It's unlikely they both have the same operating current if the sizes are different so it's safest to do this for each LED separately.

http://home.cogeco.ca/~rpaisley4/LEDcalc.html

While that will work to some degree, the batteries still won't last that long. I usually go to the local DIxieline lumber and for ~$7 use either of the 2 following Night-ize replacement bulbs, the first is like a regular bulb although it works best in a plastic screw-in socket that you can just press it in. The second link is to another model I used that is a mini-mag replacement type bulb, where I removed the whole socket and these just press in. Both of these have built-in electronics to help provide even lighting and conserve battery life. I run these even off AA batteries and get surprisingly long life.

Bulb
http://www.niteize.com/productdetail.php?category_id=28&product_id=166

The result
http://www.ratrodbikes.com/forum/viewtopic.php?f=24&t=7759&st=0&sk=t&sd=a&hilit=led+light&start=15

Mini-mag module
http://www.niteize.com/productdetail.php?category_id=28&product_id=145

The result(with an older style module new one is 1-watt)
http://www.ratrodbikes.com/forum/viewtopic.php?f=3&t=4564&p=45276#p45276

 

[chimichanga]

So Cal how did you wire the c battery set up? I saw the link but couldn't see the inside of the headlight very well.thanks

 

[socal_jack]

On most of the old lights they use the metal case as one side of the battery power, usually ground but not always, you may need to reverse power from the battery case. Anyway the metal spring that holds the front reflector in is almost always used to also get that side of power to the socket, in the photo here, it merely contacts the case of the bulb completing the the connection. The other side of power from the switch I just soldered to the bulb base after discarding the screw-in bulb socket.

Hope that helps

 

[chimichanga]

Thanks man! I'm gonna have to go to radioshack and lowes today and pick up some lights and battery holders. I don't have a dixieline close by.I think its in san diego area only.

 

[chimichanga]

Which one has a better light output?

 

[socal_jack]

I never did a side by side comparison, but you won't be disapointed with either. They both put out so much more useable light than the incandescent bulbs they came with that you can't go wrong, but I think I'd give the edge to the bulb version since it gets the light further out into the reflector. Although that could be due to the style of headlight itself.

Fry's carries alot of the Night-ize stuff also if you have one of those nearby.

 

[GodHatesCleveland]

well I made an led bicycle headlight. I used one 10 mm white LED and a 5 mm white led. They are hooked up to the switch which is also hooked up to a twoo AA battery holder. When I put in the batteries within 30 second my batteries get hot and smoke starts coming out and the led's arent even on. Eventually the batteries die. I know i did something wrong. Any help would greatly be appreciated.

You could just keep it like it is and use it to light the BBQ grill.

 

[chimichanga]

Well I got it hooked up correctly and it the batteries are doing fine! I still need to go to the store and buy the lights so cal recommended for another headlight I have. I'll post pictures tomorrow.

 

[xddorox]

yikes!

i'm planning on converting my old headlight to LED but I'm taking the cheesy way out and doing this:

http://www.howtofixbikes.ca/2007/02/how ... cycle.html

Glad to see that some are using that easy trick. I have 3 headlights set up that way and I only have one that needs battery replacement for next season.