For that application you may want to consider the Brinkman 3aaa 3w at target for 29.99.... why? Only if you're a weight weinie like me. They weigh just 129g with batteries, I use a pair of them attached permanently with stainless aircraft cable clamps on the bar ends of my all titanium hardtail urban bike. (They are very humble looking and I've lost 2 underseat bags but nobody messes with the lights- I also use a pair of Dinotte 5w lights in the center that are removable, for 16w total LED light)
Runtime's about 2 hours. I had bought a pair of elektrolumens XM-2's for that purpose but they were too bulky.
to carry around I'd say the brinkman is a crappy looking little plastic light. to strap to a bike and forget about they function great.
Oh, and I have them pointing to cross beams about 100ft in front, good throw as well.