Bulbs for 36, 48, and 60 Volt electric scooters and bikes
are rated for a higher Voltage than the scooter or bike is.
The reason for this is that when electric scooter or
bike battery pack is recharged its Voltage is higher than normal, and then its Voltage
slowly drops down to normal while the vehicle is being driven.
For example a 48 Volt battery pack will have 55
Volts in it after it has been recharged. So if a 48 Volt bulb was used then it
would burn out earlier than normal since it was being run on 55 Volts.