Originally Posted by ColinL

How much runtime do you want? I'm using some single 18650 LED flashlights (Ultrafire WF-502b) and they are super bright with a great pattern, but they have less than 90 minutes of life. Fine for my morning fitness ride, terrible for serious nighttime use.

You need systems with external batteries if you want bright and 2+ hours of life.

I would give up the USB charging requirement. That will limit you to either really small lights, or really long charge times.


BTW: there's a lights & gadgets forum here on BF. Very good tips and specific product recommendations there.