Ultimate Luxeon K2 bike lights (in progress)

So after my recent set of mountain bike lights, I decided that I was ready to build what would be my be-all, end-all set of bike lights. These would be it. The Ultimate.

After the mountain bike lights, I wanted lighter, brighter, and longer battery life. I wanted to be able to use them for long road rides - so they can't use a bottle cage. I wanted to be able to commute without having to charge the battery every night. I wanted even more power for mountain bike riding and scaring pedestrians. I wanted lighter weight, so I could use them for fast group rides.

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The requirements that I wanted to meet were:

• Less than 200g weight for the whole system with an hour of battery life (at 3W output power)
• Light output competitive with a 20W halogen
• Batteries mounted somewhere other than the bottle cage
• A little light for the bike computer
• Some indication of the battery charge level
• Handlebar-mounted controls
• Robust design - nothing should be mounted purely with hot glue

So the big changes here are:

• Li-ion battery pack and charger. These are lightweight and have great energy density. I have a few packs - a small one for commuting and club rides, larger ones for endurance mountain biking, adventure racing, and Audax rides.
• Better LEDs and lenses. After playing with Cree XLamps, I decided that I'd be better off going with the most efficient LEDs I could find, even if it meant paying more. So I went with Luxeon K2 devices and the Fraen lenses I was using originally.