How Do Magnetic Bicycle Lights Work?

Magnetic lights do not require batteries to provide illumination while riding a bicycle. As the wheel of your bicycle turns, magnets attached both to the frame and wheel generate electricity that powers the light.

Electrodynamic Induction

When a magnet spins inside a coil of conductive wire, an electrical current will flow through the wire, acting as a generator. Known as electrodynamic induction, this principle is used to produce electricity that operates a magnetic bicycle light.

Installation

Typically, a magnetic bicycle light consists of the light itself connected by an electrical wire to a magnet and coil assembly that attaches to the front fork of the bicycle. Another magnet, called the driver magnet, attaches to the spokes of the front wheel.

Operation

When the front wheel of the bicycle turns, the driver magnet passes by the other magnet within the coil that is attached to the fork. This causes the magnet in the coil to spin, generating electricity, which powers the light.

Storage

In some models of magnetic bicycle lights, electronics within the unit also store energy within a rechargeable battery or capacitor. This stored energy is then used to supplement the electricity needed to power the light when riding more slowly or when at a stop.

References

• Freelights: Battery-less Bicycle Flashing Lights
• Magten Light: Installation Instructions
• Reelight Battery-Free Bike Lights: Technology