Introduction: Mountain Bike LED Light Bar W/ Makita Battery

With summer soon approaching in Australia, the appeal to ride in the cool of the night is evident. Although the cost of a decent bike light is a minimum of $200-300. This guide will show you how to develop a mountain bike light utilising a small LED light bar (usually used for 4WD's) and a cordless drill battery for under $100.

Step 1: Materials

For this project, you will need:

  • Small LED Light Bar - preferably with spot and flood light combination
    For this project I used a STEDI ST3501 6.5 inch 30W super slim LED light bar (as pictured) for $60
  • Makita battery terminal: part number 643838-6
  • 3D printed battery mount (see attached)
    For this project I adapted a design by GPlatek:
    I added two holes 64mm apart so that the battery mount could be attached to where the drink bottle holder would normally sit.
  • Cable ties, female spade connector, M5 0.8mm spaced 20mm bolts

Step 2: Assembly

  • File back the 3D printed battery mount to enable the battery terminal to be inserted - it will be a tight fit
  • Attach the wires from the light bar to female spade connectors and crimp/solder together and then connect to the male spade connectors on the terminal (pos and neg terminals specific)
  • Mount the assembly onto the bike using the bolts
  • Using cable ties, tidy the cables to the underneath of the bike
  • Mount the light bar to the handlebars, options include:
    • Use the standard brackets that come with the light bar, using thick cable ties and a rubber strip to protect paint
    • Purchase a light bar tube clamp style bracket (as pictured) - measure the thickness of your handlebars prior
  • Additional features you may wish to include:
    • On/Off switch
    • Dimmer switch

Step 3: Test and Enjoy

I found that a 1.5 amp hour 18V Makita battery powered my 6.5" light bar for almost 2 hours before I noticed dimming.

You may have a different brand of drill battery that you wish to use and I am sure there are plenty of other 3D printing designs out there which you can adapt to suit your needs.