What is e-bike wattage?
E-bike wattage is the power output of the on-board motor. The rating is the voltage (V) supplied by the battery multiplied by the maximum current (amps) flowing from the battery to the motor. For example, a 36V battery and a 15A controller is equivalent to an e-bike motor with an output of 540W.
It's worth checking the fine print to see how ebikes manufacturers calculate their motor output. Not everyone uses the same method to calculate the rating of their bikes. Most use what is called the maximum continuous output of the motor - an output that the motor can continue to produce without overheating or breaking. Remember, one person's 250W e-bike is probably another person's 500W e-bike.
Also, don't confuse e-bike motor power with e-bike battery rating. Often, you will see it referred to as Wh or watt hours. What is the battery capacity, or more specifically, how many watts per hour it can deliver to the motor.
In most cases, oem electric bike batteries are between 300Wh and 500Wh. As battery technology advances, 750Wh batteries are becoming more common. Some e-bikes even have two battery ports to maximize riding range
More wattage = better e-bike?
An age-old question - is more better? In the case of wattage and e-bike motors, it depends. An e-bike motor with a high wattage output will provide faster acceleration, be smoother on hills, and generally provide better performance for heavier riders.
But just as high-performance cars aren't usually as efficient as everyday small speedboats, the same is true for e-bikes. A motor with a higher power rating will drain the battery more quickly, resulting in a shorter ride for the rider.
How many watts is a good e-bike?
Generally speaking, a 250W e-bike motor will provide the average cyclist with enough power to ride at a leisurely pace on relatively flat terrain. Adding additional variables such as heavier riders, higher desired speeds and hill loads, and a higher powered e-bike motor may be better.
Be sure to also understand the legal requirements for e-bikes from the electric bike factory in your country before you buy. In the UK, electric bicycles or "electric assisted pedal cycles" (EAPC) are not allowed to produce more than 250W of maximum continuous power. The same applies in the European Union. In the US (different states have different regulations), this number rises to 750W.