Watts
Power for electric scooters is usually measured in watts.
A human climbing a flight of stairs is doing work at the rate of about 200 watts. A first class athlete can work at up to approximately 500 watts for 30 minutes. An automobile engine produces mechanical energy at a rate of 25,000 watts (approximately 30 horsepower) while cruising.
One horsepower equals 746 watts
 Electric scooter motors and controllers handle power differently for continuous riding versus short-term ‘peak’ riding moments.
 The more watts your electric scooter's motor can produce the better buffer you have for expecting ‘cool running’ and long term reliability.
 The electric scooter's motor controller is an integral part of an electric scooter’s power capabilities. No matter how powerful the motor is (watts capability) it will perform at no greater level than the controller allows. No matter how powerful the controller is that is connected to a electric scooters  motor, the motor will not perform greater than it’s designed parameters unless the voltage is raised above it’s design parameters, which will result in motor failure.
 The range of an electric scooter is determined by how many watts are required to complete the journey.
 Watts can be measured by multiplying the battery voltage by the amount of current (amps) that are required to do the work. The harder the work … heavy rider/scooter, fast speeds, hill climbing, many stops and starts.. the more amps that are used, the more watts used.   
  It is best to purchase a scooter that exceeds your needs rather than meets your needs, as the one that meets your needs is probably being run near the ‘red line’.


Amps
The power rating of an electric scooter's motor is determined by its operating voltage (volts) and on its current handling capacity (amps) at that operating voltage. The unit of measure is the ‘watt’
 Usually an electric scooter motor can handle significantly more power (watts) for a short period of time versus operating continuously.
 The amount of power a motor can handle for a short period of time (seconds or minutes) is called ‘peak’ power and the amount of power the motor can handle continuously (hours – days) is called ‘continuous’ power.
 The higher the wattage of the motor the higher the voltage or current has to be.
 The device that must supply the motor with all the voltage and current it needs (watts) is the battery.
 A electric scooter motor powered by a battery has a capacity limited to the power capacity (voltage x current output per hour ‘ah’) of the battery.
 An electric scooter motor is an electro-mechanical device that by design is limited to the amount of current (amps) it can draw (internal resistance).
 The input power of a motor is simply the amount of wattage it takes to operate.
 The output power of a motor is the amount of wattage the scooter's motor offers towards doing work.
 The ratio of input power to output power if called the efficiency of the motor. One obviously hopes to get as much power out of a motor as ones put into a motor, but there are no 100% efficient motors. The higher the efficiency the better.
 The power lost between input power and output power turns up as heat. Heat is an enemy to all motors and can lead to breakdown if not kept within safety limits.
 If a motor can be cooled effectively its power rating can be pushed above normal operating limits.

Electric Scooter Batteries
Sealed lead acid batteries are the corner stone of the electric vehicle market, but they are also its greatest limiter for expanding performance. 
SLA are like car batteries except their is no liquid acid to spill and corrode. They use a 'paste' and the unit is sealed with nothing other than the terminals exposed.
If you want reliability, simple charging, and power at a cheap price, they are the only game in town. They take up a lot of space, however, and one gets into 'diminishing returns' by adding more and more batteries for more range. The extra weight eventually negates the extra power gain.