Battery Versus Dynamo Lights


California vehicle code mandates that any bike operated in darkness is required to have a front headlight that emits a white beam visible from 300 feet and a red rear reflector that’s visible from 500 feet when illuminated by motor vehicle high beams. The law also mandates reflectors on both pedals or the rider’s ankles, and side reflectors or tires with reflective sidewalls. The headlight can be attached to either the bicycle or the rider. Check the vehicle code for the jurisdiction in which you ride to be sure you’re meeting at least the minimum requirements.

Battery-Powered Lights
The simplest and least expensive lighting set-up is a white LED headlight on the front, and a red blinking LED on the back. Small, but surprisingly powerful, AA- and AAA-powered lights are available for under $50 each. Mount the headlight on your handlebar and the red blinkie on your seat post (or rack), and you’re good to go. I also highly recommend rechargeable batteries and a battery charger as part of any battery-powered lighting system. View my post on minimalist lighting systems for more on battery-powered lights.

Planet Bike Blaze 2W

Dynamo-Powered Lights
For those who regularly ride in the dark, a dynamo lighting system provides reliable, battery-free lighting that’s always available at the flip of a switch. Power is provided by either a bottle or hub dynamo. Bottle dynamos mount on the bicycle frame and have a small roller that rotates against the tire to generate current. Hub dynamos (aka generator hubs) have the generator built right into the hub. In recent years, hub dynamos have far surpassed bottle dynamos in efficiency and popularity. Dynamo lighting systems are more expensive than small battery-powered systems, and unless they come pre-installed from the factory, they also require a more involved installation process. That said, they provide the benefit of always-available lighting, a real advantage for everyday, year-around commuting and utility use.

Battery Lights
Easily moved from bike to bike
Require batteries
Easily stolen

Dynamo Lights
Always available (like automobile lights)
Bolted to bike (semi-theft proof)
Relatively expensive
Can be tricky to install
Not easily moved from bike to bike

After using mostly battery-powered lights for the past couple of years, I’ve recently returned to running a dynamo system. Despite the above mentioned drawbacks, I’m quite pleased to be battery-free again; it’s hard to overstate the convenience and confidence that comes with always-available, high-quality lighting.

My current favorite dynamo headlight is the E3 Pro from Supernova. The beam provides an excellent compromise between coverage and intensity, and the housing, emitter, and wires are exceptionally high-quality. Combined with any decent dynamo hub (I’m running a Shimano Alfine), it makes for a high performing and reliable set-up. You can read more about the E3 Pro and its matching tail light in my review from a couple of months ago.

© 2011 EcoVelo™