Bicycle USB chargers use your own pedal power to charge your mobile devices while cycling. Your pedal power is first captured by the sidewall dynamo. Then, it is converted into the usable charging power by the bicycle USB charger. This power can be used to charge your mobile devices such as smartphones, rechargeable bike lights and batteries, GPS units, and other USB-chargeable devices.
Bicycle USB chargers are simple to install and easy to use, and can be attached or removed in minutes. They are appropriate for any level of cyclists, and fit most common bicycle frames.