I can add something about the reason alot of chinese LED are rated 12v to 80v DC.Its for the variety of electric bicycles and scooters,of which China is surely the world leader.I buy these type of lights for my ebike, its an all encompassing system for many different vehicles. The higher the volts in your battery pack,the more power to your drive-train.The battery systems are configured by series-parallel combinations for power and capacity. For example,the trusty old golf carts were 36v,maybe more now.I have a 48v battery on my ebike,next battery I could go bigger.When you crank my throttle,you can release up to 1000 watts power in my system,compared to a human who can pedal maybe 100 watts continuous. Battery volt systems on ebikes now are getting higher and higher for power as the tech progresses,like that needed to climb steep hills like an enduro 250cc! Here in N. america,they want you to buy their specialized ,volt specific rated ebike lights for 10 times the price.. Mysterious stuff so trust them. On my ebike,I run a 5 watt tailight and 18 watt headlight (their rating, i forgot the lumens),both 12v to 80v. Couldnt find bright ebike lights like this here anyways. Works great ,2 years now despite all the vibration as I like to ride off road.My on board real time system analyzer says they are only drawing 2 watts from the battery.Those LED draw little power,its hard to figure out all the different ways that LED are rated world wide!But my system analyzer doesn't lie about the actual real time power used from the battery and they're motorcycle style brightness,the brightest bicycle lights you can imagine. Probably illegal on a bicycle here.Only drawback,water resistant but not waterproof,no O rings.Total cost....$20 free shipping..