While waiting for my bike to arrive I'm thinking about lights for riding down the Cambridgeshire Guided Busway. As it's seriously dark out there (miles from an artificial light source) I'm tempted to get on of those LED10 Cree U2 units from BangGood that dv8eh mentioned. Can they easily be wired in to the Tourer's wiring, ideally without voiding the warranty? If not, I'll rig something up with a pile of AA NiMH cells left over from last year's PiWars robot competition, but it's one more thing I have to remember to charge. As I understand it, the built lights also have their own batteries.