What Are Electric Bikes and How Do They Work?

In-depth analysis of an e-bike construction and parts with FAQ section.
John Watson
John Watson
John is an experienced cycling enthusiast and a great asset when it comes to writing skills. He's a Bachelor of Arts and a talented journalist. John is in charge of our blog read more
Reviewed By
Jessica Kingston
Jessica Kingston
Expert Consultant
Jessica is our expert consultant on all things connected to biking - gear, technique, you name it. Being a pro cyclist in the past, she knows exactly how things work in and read more
Last updated: August 08, 2023
Bike The Site is reader-supported. We may earn a commission through products purchased using links on this page. Learn more about our process here

If you have ever asked yourself, how do electric bikes work? It might be because you are thinking of getting one of these handy devices. Knowing more about how this cool technology works can make it much easier to decide if this is the right kind of bike for your needs.

Electric bikes can be ideal for those who want to ride their bike with ease, and they do not have to be used for commuting. There are various reasons that you might want to get this kind of bike, and as the cost of these helpful devices becomes increasingly reasonable, there is no reason not to get one if you have always wanted to. This guide will help you understand how electric assist bikes work and make sure that you are educated about their use and benefits before you invest in one.

If you are ready to learn more about these kinds of high-tech bikes and what they can do for you, you need to keep reading.

The Concept and How It Works

What Are Electric Bikes and How Do They Work?

The concept of an electric bike is really simple. This device works just like a regular bike but offers an electrical component that augments the human power that is making the bike work. The electrical part of the bike’s operation is just a perk, but it does not replace the need to pedal and steer the bike.

An electric bike works by taking the energy from a battery mounted on the bike and using calculations to determine how much power assistance you need while you ride. This is done by the motor that is housed centrally on the bike. This is often called a mid-drive motor, and it can be placed on the front or the rear hub as well. As you pedal, a torque sensor measures your effort and then matches it to the motor’s output. This creates balanced assistance to your riding that helps you save energy and makes riding the bike easier and more efficient.

This kind of bike is becoming an increasingly smart commuter choice in cities as the cost of gas and parking has gone up and up. Being able to ride your bike with minimal effort to and for work or to and from the store can make this a very attractive choice when compared to more traditional bike riding. You will enjoy a pleasant assist from your e-bike that will make it possible to get to work without being sweaty, and you can save your energy as you take care of your daily errands and routines.

If you are not a fan of riding a bike in a general sense, an electric bicycle can change the way that you feel about this kind of experience. The difference that is made by having a slight assist as your ride can be key in finding a way to enjoy your bike riding hours in ways that you never have before.

Key Parts

There are some key parts of an electric bike that are essential to the way that it works. You will need to know some more about these parts before you can start shopping for the best electric mountain bikes under $3000 or for the best electric bikes for hills. The more that you know about the bike and how it works, the easier it will be to shop for one. You cannot hope to find the right bike for your needs if you don’t know much about how these bicycles work.

There are various models of electric bikes on the market these days, and you can easily shop for mountain-style bikes, road bikes, and more. This is part of why you need to know a little bit about how an e-bike works before you start looking for the bike that is best for your situation.


What Are Electric Bikes and How Do They Work?

The battery on your bike can impact the range of the bike, and it can also impact the weight and the style of the bike.  There are two common battery types for e-bikes. The two types are SLA batteries and Lithium batteries.

SLA vs lithium

  • Sealed Lead Acid (SLA)

This battery is inexpensive, but it is heavy and can be bulky. It also offers a short-riding range, and it will need more maintenance than other battery types. It will need to be charged immediately after each use.

  • Lithium – Ion/Polymer/Manganese

This is the newest technology in batteries. This kind of battery has about 2-3 times the life of an SLA battery, and they are lighter and much easier to maintain. This kind of battery will also hold more charge and will charge up more quickly after each use.

Most electric bikes still use this kind of battery. You might want to shop for a lithium battery if you want to upgrade your charging and battery life experience. You will pay more for this improved battery style, so you will need to be prepared for this added cost. However, you might get enough benefit from the lithium battery in your daily use of your bike that the cost will be offset right away. Lithium batteries are less expensive than they used to be, but the cost of these batteries has not come done to the level of the SLA battery as of yet.

Batteries can give you a range of 20-100 miles on a full charge. The capacity of the battery and the kind of terrain you are navigating can impact the riding hours that you will get per charge. Some bike systems will give you an estimated range as you ride, which can help you to regulate how you are riding. If you do not have this guide as you ride, you will need to be sure that you know what the average life of your battery is and take this into consideration when you take long rides.

There are some bike models that allow you to plug in an additional battery that can fit inside a bottle-style cage. This can be a good benefit if you are going to take a ride that is longer than usual or if you are worried about climbing hills. The estimated range for your bike is just a best guess based on average riding hours and terrain. Being sure that you have a back-up battery can be a big benefit when it comes to using your e-bike on a regular basis. This can also be a help as your bike’s battery ages and starts to hold less charge than it did before. This is not as much of a concern as it once was because battery technology has improved greatly over the years. However, the age of the battery on your bike can still impact performance over time.

Voltage and amp hours explained

One of the most common questions that people have about e-bikes is what voltage and amp hours have to do with the function of their bike. Watts come from the battery voltage on your bike. The motor controller creates the amps. As a simple example, a bike that has a 52-volt battery and a 20-amp controller will create a wattage of 1,040 watts.

Voltage is the power that the battery can send to the bike’s motor. High voltage means that more power can flow from the batter to the motor in a shorter amount of time. This increases performance. Amp-hours tell you how long the battery will run prior to needing a charge.

Using another example, it will take 5.2 hours to recharge a 13 amp battery from 10% charge to 90% charge. There are ultra-fast charging units that you can invest in, which can decrease your charging time greatly. However, knowing what the base charging time for your bike will be can make a big difference. This is particularly true if you have to ride your bike a long distance each day and you are worried about running out of charge and having to pedal unassisted the whole time you are riding once the charge has run out.


What Are Electric Bikes and How Do They Work?

There are a few places that the motor can be located on your electric assist bike.  The front or rear hub can be an ideal location, but the motor can also be mid-drive. The motor will have a power rating that ranges from around 200W to 1,000W. When considering how electric bikes work on hills or when shopping for an electric mountain bike, you might need to focus on this part of the motor’s specs to be sure that you are getting the right kind of bike for your needs. Commuter riding will probably not necessitate as much of an assist as you ride unless you like in a place with lots of hilly streets to climb.

Hub motors are the most common design style, and these are generally integrated into the front or back wheel. These motors push or pull the wheel along as you ride. This system is not connected to the bike’s gears, however, which means that it is not as efficient when climbing or riding very fast.

Full power vs pedal-assist

Pedal assist is sometimes also called electric assist. This mode can be accessed when you turn this mode on via the handlebars on the bike. This allows the motor to provide electric power while you are pedaling. This makes it much easier to pedal and flattens out hills. There are often three levels of pedal assist, low, medium, and high.

Full power is when you elect to have the bike motor do all the work while you just rest. This is usually capped and limited to 20 mph by federal law. This will also use up more of the battery that your bike has to offer. Usually, the best electric cargo bikes provide this feature, as it is much harder to pedal while carrying heavy weight on you.

Wattage explained

Wattage is the power output of any motor. The wattage of your bike will be listed as peak and nominal power when you are looking into the power potential of your bike motor. These ratings are usually based on an ideal calculation that includes the average operating conditions that you might use your bike in.

Peak power is calculated based on when the motor is under full throttle and is being used in ideal operating conditions. This value will likely never be achieved when using your bike in the real world. Realistic power is the power that you will get from the motor is related to the nominal wattage, which is 75% of the peak operating power. This is the number that you will want to use when calculating watt-hours.


What Are Electric Bikes and How Do They Work?

The sensor is the item that measures the effort that you are putting in as you pedal. The sensor matches the bike’s output to your effort. This is how you get a solid and consistent assist as you pedal. The sensor helps to make sure that you are getting the most out of your time riding your bike. This is one of the parts of your bike that needs to be working properly for you to get the most out of your riding experience.


Which is better: hub motor or mid-drive motor?

Hub motors provide propulsion by making the wheel accelerate. Mid-drive motors increase the power of the pedal stroke. Mid-drive motors are the most efficient and are also the best option for power-to-weight ratio. Mid-drive motors are integrated with the crank and gears, which also makes them much less likely to add weight and bulk to the bike.

How do you charge an e-bike?

To charge an e-bike, the battery pack will need to be removed from the bike, it will need to be turned off, and then the battery pack can be connected to the charger.

Do I need a license to ride one?

You will need to be a minimum of 16 in most states to be able to ride an e-bike. You will also not be required to wear a helmet when you ride one in some places. These bikes are still fairly new in the US, and the process of making laws has not caught up to them yet. There might be changes to these rules in the future.

Final Thoughts

Electric bikes are a very efficient way to get to work, to get around campus, or to head out to run errands. As the cost of car ownership and fuel prices increase exponentially, many people start to wonder if electric bikes are the right answer for them for their daily commutes and errands. Answering how do electric bikes work should be really easy for you now. This guide will have taught you a lot about this kind of bicycle and how it can work to help make your days easier and more cost-efficient.

An electric bike can be the best choice for those who want to enjoy riding their bike without making a huge effort and for those who need to get around rapidly without the use of a car. Electric bikes are a very cost effective and safe solution for easy and enjoyable hours on your bike each day.


Leave a comment

Your email address will not be published. Required fields are marked *