Regarding adding lights to scooters & bicycles ...
What I've done is use LED lighting they carry at auto parts stores. Because small scooters & bicycles aren't regulated so tightly it's not necessary to make sure your lights are DOT certified, unlike on a motorcycle. And at the auto parts stores they have many LED based marker lights and accent lights. Low power, bright, long lasting, what's not to love. If only there were DOT certified LED headlights...sigh
Anyway, the units are 12 volts apiece. What I do is wire them in series to match the pack voltage of the vehicle. A 24v vehicle, wire two in series, a 36v vehicle, wire three in series, etc.
At Kragens they carry a white light bar they call "accent lighting" but to my eye it's a perfect headlight. My bicycle has three of them stacked on a bracket dangling from the handlebars. For tail-lights the bicycle has three red marker lights, on a bracket, dangling from the cargo panniers frame.
The headlights are bright enough to read a book by, and even light up the road to a decent distance. This is totally unlike the dinky bicycle lights that are usually used. I figger, if I'm gonna carry that big battery pack I might as well carry a significant lighting system. Why limit the bicycle to dinky lights?