Upgrading a Vintage Bicycle Headlamp With USB-C and LED Lights

Hello Makers! In this Instructable, I'm going to show you how I took a non-functional, rusty VINTAGE bike light and transformed it into a modern, rechargeable LED headlamp. This project was requested by a follower who restores old bikes and needed an upgrade .

If you prefer to watch the full, entertaining (and sometimes chaotic) process, you can find the complete video on my YouTube channel, @dariocose.

This is a perfect project if you’re looking for a lazy, cheap, and slightly superficial way to give a second life to old items. Let’s get started!

- My Cool 3d Pritner #1

- My Cool 3d Pritner #2

- Chinese bike lights

- Mini Welding Workbench

- Cool Knife

- T12 Soldering Station

- Button

- Type-C Female

- Toilet paper

- Magic Liquid

The problem is clear: the vintage headlamp is old, rusty, and uses old components (if any). The goal is to install modern, powerful LED lights and, crucially, a simple, modern way to recharge them.

Instead of designing a custom PCB from scratch (it’s still summer in Italy, and I want to go to the beach!) , the quickest and most economical solution is to cannibalize cheap, pre-made Chinese LED bike lights.

These cheap lights come with a built-in rechargeable battery, charging circuit, and LED driver.

Our solution is to:

1. Carefully extract the internal LED/battery circuit board from the cheap light.
2. Modify the circuit by replacing the tiny stock button and charge port with new, external components.
3. Design and 3D print a new custom case to securely house the modified circuit inside the vintage shell.
4. The final result will be a bright, USB-C rechargeable bike light that maintains its vintage look."

Disassemble the Vintage and Donor Lights First, we need to take apart both lights. The vintage light usually only requires removing a few old, rusty screws to expose the reflector and the inner shell. The donor light (the cheap Chinese light) will require some patience, as the case is usually glued shut. I had to use screwdrivers, pliers, and even my cool Tanto knife to get it open!

Once opened, remove the main circuit board. You will notice it has a small, low-capacity battery (around 160-180 mAh), an integrated charge circuit, a tiny button, and a small USB connector.

To make the light usable without disassembling the headlamp every time, we need to extend the button and the USB charge port to the outside of the case.

1. Safety First: Desolder the battery from the circuit board to prevent any short circuits.
2. Desoldering: Remove the original surface-mount button and the multi-pin USB connector. (A small, solid support arm, like my new one, makes this job much easier than a simple octopus holder) .
3. Wiring the Button: Solder two short wires (about 8cm) to the original button contacts on the PCB, and connect them to a new, larger button.
4. Wiring the USB-C Connector: Examine the USB-C pinout. We only need the positive and negative power connections. The best connection points are typically on the outer pins of the connector's solder pads (Pin B9 for positive and A12 for negative). Solder two wires to these points and attach them to your new USB-C panel-mount connector.
5. Final Check: Solder the battery back on and test the circuit! The LED should flash when the button is pressed, indicating that everything is working.

Since the circuit board won't fit perfectly or securely inside the vintage shell, we need a custom housing. I used my new, faster 3D printer to design and print a custom mounting bracket.

My initial design tried to imitate the original shell, but it wasn't solid enough. So, I created a new, more regular-shaped design that:

1. Allows for printing without the need for supports.
2. Securely holds the circuit board using small M3 bolts.
3. Provides dedicated slots for the new external button and the USB-C connector.

Key Tip: Make sure to install the USB-C connector into the 3D-printed case before soldering the wires to it. It’s always easier to solder with the component fixed in place!

The final assembly is all about securing the components.

1. Fix the PCB: Place the circuit board inside the 3D-printed case and secure it with small M3 bolts and brackets.
2. Cable Management and Protection: Apply heat shrink tubing to all the soldered wires to protect them.
3. The 'Superficial' Way: Use a large amount of hot glue to secure the battery and the cables within the casing. (My final light is primarily made of hot glue and weighs about 20 kilos!)
4. Vintage Shell Reassembly: Place the complete 3D-printed assembly into the vintage headlamp shell.

The Finishing Touch: I noticed one of the original screws was a rusty wood screw. I decided to upgrade this small detail by soldering an M3 bolt to a washer, creating a much cleaner and shinier fastening screw!

With the light finally reassembled, it’s time to test our creation at night!

The visibility is significantly better than the original lamp. In one afternoon, and for just a few dollars, we successfully gave new life to an old object, transforming it into a modern, functional, and rechargeable LED bike light.

This project confirms that you don't always need a complicated, professional solution; sometimes, the lazy, cheap, and creative approach works just as well.

I hope Tommy is happy with the job!

Thank you for following along! If you enjoyed this project, don't forget to subscribe to my channel and check the links in the description for component sourcing!