Skip to content


Understanding How Watts, Volts, and Amp Hours Affect E-Bikes

Understanding How Watts, Volts, and Amp Hours Affect E-Bikes

The decision to invest in an electric bike is easier if you completely understand the bike’s performance power. These measurements break down into watts, volts, and amp hours and apply to the motor and battery life. A significant part of owning an e-bike is proper care and maintenance of these functions, which enable you to optimize lifespan and overall functionality.

Whether you’re beginning the search for an electric bike or looking to upgrade your existing ride, understanding how watts, volts, and amp hours affect e-bikes is a great place to start. Let’s take a closer look!

Watts and Performance

The watt measurement for an e-bike refers to how much continuous energy the motor can consume or spend. Sometimes, a peak watt reading will describe usage or consumption from short intervals, different from a constant read. A bike’s motor will reach its peak during high stress, such as climbing steep hills.

A key thing to note while reviewing a bike’s wattage is how this impacts its performance. A good rule of thumb is the higher the watt read, the further and faster the bike will travel. With that in mind, also consider how the bike reports the watts—continuous or peak. The bike’s configuration will change the way it uses and consumes energy, affecting the watt read.

Let’s compare watts with horsepower to take a closer look. One unit of horsepower is the same as 745.7 watts. This means the following for e-bikes:

  • An e-bike with 250 watts has .33 horsepower
  • An e-bike with 500 watts has .67 horsepower
  • An e-bike with 750 watts has 1 horsepower
  • An e-bike with 1,000 watts has 1.34 horsepower

These comparisons are essential in understanding a specific bike’s performance ratings and converting it to the optimal wattage.


One of the most significant ways to determine an e-bike’s configuration and how this impacts power is by looking at the hub-drive or mid-drive aspects. These two features make a difference in the motor’s rating.

A hub-drive motor sits in one of the bike’s wheels and provides a propulsion effect to whichever wheel it’s on. This was one of the most popular electric bike configurations when they began gaining momentum in the market.

A mid-drive motor uses the bike’s drivetrain to provide power, usually through the crankset. These mid-drive configurations work with the bike’s existing gears and amplify their mechanical advantages. This can benefit the bike and rider when encountering steep hills or periods of long inclining.

So, what does this mean for a watt rating? A mid-drive motor bike with a continuous power read of 350W could have more power than a hub-drive bike with 500 to 750W. If you’re struggling to find the bike’s watt read, you can use a mathematical equation to find watts by multiplying amps times volts.

Volts and Performance

The second power measurement worth understanding is the volts. The more volts a bike has, the more overall power it possesses. Volts will also refer to the amount of pressure a battery can contain and are typically measurable in sequences from 12V, 24V, 36V, and 48V. The average electric bike includes 24 volts, enabling it to cruise around town, and is also known as a commuter bike.

A bike to get up hills and across varied terrain will require more power in volts from 36V or higher. Review our collection of high-voltage Stealth electric bikes for sale. These electric mountain bikes feature higher voltage reads accompanied by all-terrain tires, making exploring the outdoors more enjoyable.

Understanding how to navigate the voltage reads is an essential step in optimizing performance, and this also increases the likelihood of the bike’s motor and battery working cohesively.

Amp Hours and Performance

To measure an e-bike’s electrical current, you refer to its amps. The terms amps or amp hours refer to the battery’s capacity, which is the overall power the battery can hold, and amp hours will vary in size based on the capacity.

Essentially, the number of amp hours a battery can hold is like the bike’s gas tank. These numbers will determine the bike’s distance as far as range and mileage, as well as the amount of charge it can withstand.

Various factors weigh on an electric bike’s range, like climbing hills, cargo weight, and strong winds. Additionally, the mileage alters after factoring in overall speed, starting and stopping, and rider weight. An excellent way to determine the amp hours necessary is to evaluate your riding requirements and purpose for an electric bike. These lifestyle demands will help you select the proper and most adequate battery needs for optimal performance.

How Much Power Does an E-bike Need?

Now that we understand how watts, volts, and amp hours affect e-bikes, we can find the most suitable option for your riding style. A leisure rider can begin with 10-amp hours, which will enable you to travel roughly 20 to 40 miles. But we know that things such as weather, cargo, weight, and speed will determine if it’s closer to 20 or 40.

If you know right away you will travel with heavy cargo, at altering speeds, or across varied terrain, consider bumping up the amp hours to accommodate these factors. Additionally, it’s worth noting that riders and bikes are not an exact science, so accommodating the amps per lifestyle specifications can alleviate any incidents of decreased power.


Depending on your residing state and the place you will ride your electric bike the most, knowing the power and classification of your bike is essential for safety. There are three classifications for an e-bike, and these correlate to its powering functions.

  • Class 1 e-bike features a pedal assist and a top speed of only 20mph.
  • Class 2 e-bikes can run by the motor alone with a powered speed maxed out at 20mph.
  • Class 3 e-bike features a pedal assist and a top speed of 28 mph.

These regulations help bring safety to any electric bike rider who intends to commute within their community while understanding these are not like motorcycles. Low-powered electric bikes do not need insurance or special licensing.

Final Thoughts

When we look at these three components and how they affect your electric bike, we understand how vital it is to find a bike that can meet your needs and optimize your performance. Compared to buying a traditional bicycle where you are the powering system, an electric bike offers many benefits to riders, from power assistance, decreased visits to the gas pump, and more convenient exercise sessions.

Reach out to Voltaire Cycles today to learn more about our selection of e-bikes and how these three components interact when you are making your selection.

Understanding How Watts, Volts, and Amp Hours Affect E-Bikes
Previous article Pedal vs. Throttle: Which Is Better for an E-Bike?