Actually, this is so complicated and high maintenence sounding I think I'm going to go with the cheapo handlebar mounted flashlight version. Uses double A batteries, good starter kit. I have a special talent for killing expensive rechargable batteries. I also live at a lower latitude and we don't get as dark as early. I'm still coming back after injury and night riding is a hardbodies game, so it isn't urgent.
I was just curious about them and the night vision thing. I'd explain it if I could, but you really need to be out at night and tell people where to look. It's about looking at the edges of things, defining shapes by the light behind them or... It's hard to write down. Bet it's in the Girl Scouts manual.
I thought every body knew about this, it was the rage in Mt biking maybe 6,7 years ago. Guess it blew over. Not good for actual mountains?

Lizzy