5Watt LED Bike Light Project
Challenge: To build a very high brightness LED based bike light.


  • LED: 5 Watt ProLight Star
  • Optics: 45 Degree Collimator or 20/30 Degree Reflector
  • LED Enclosure: Custom Machined Aluminium


  • 5Watt Cool White LED, equiv to 20 watt halogen.
  • Lightweight & compact, 490 grams including battery.
  • Long burn time, up to 9 hours.


Fitted the LED to the aluminium holder, fits perfectly! The next one will be basically the finished unit, which will be slightly bigger to hold the driver electronics and will also have fins to aid dissipating the heat. It will also mount the LED better inside without the need for the M3 bolts i am using in this prototype. Weight is currently 426g.

Had prototype v2 machined up, spotted a few problems and redesigned.

Prototype v3 machined, this is now very close to the production light, weight is now 490grams with battery and mount. This design now has integrated electronics and a rotary on/off switch.


Lens holder, LED & Lens

Assembled Unit

Powered Up

Powered without the lens.

4Ah Li-Ion Battery Pack

The LED in the back garden, this looks a little brighter than it really is.

Working Prototype #1 - The LED holder.

Working Prototype #1 - Mounted on Bike (using an old CatEye reflector mounting bracket. Of course this is just for testing purposes, it's hardly weather proof.

2nd February 2006

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