Okay, then how about something from Cygolite? The
expillion series offers cordless design and the ability to swap cells. The
Trion 600 has 3 LED's, has a claimed 2.5 hours on high in it's cordless design with the option to run an external battery pack. Don't know run times with the external pack, but possibly two external packs, combined with the internal will give sufficient run time.