Batteries don't last and you need access to them in order to replace them, making theft easier. There are systems that integrate a dynamo in the chassis of the

Batteries don't last and you need access to them in order to replace them, making theft easier. There are systems that integrate a dynamo in the chassis of the bike. It's also more environmentally friendly because you provide the power for the lamp. The article mentions there already is a battery in place powered by either solar or dynamo.