The rechargeable batteries are very feasible but keep in mind the time it takes to charge them. It takes 4-6 hours even at the 500mA maximum "rapid" charge rate! Unless your going to be on a tour lasting several days or a week, way out in the "jungle or outback" where you cant purchase batteries, and don’t mind "dragging" batteries day and night to charge them, I'd just put up with the lights going dead at stops and use Blinkies on the handlebar and rear rack!