How long will a single charge last?

Depends on the item and mode that the light is on:

            Boulevard: high steady-4 hrs front; 3 hrs rear

             Avenue COB: high steady-3hrs 45min front & rear

             Avenue Dual: high steady-1.5 hrs

              Street : high steady-1.5 hrs front & rear

             Alley: high steady-2.5 hrs front; 1 hr rear