Recovering energy under braking is an awesome way to grab some extra charge, but how does regenerative braking actually work?
Regenerative braking was first used in 1967 by the American Motors Corporation. Despite being a revolutionary idea designed to increase the vehicle's range, it didn't catch on until hybrid and electric vehicles became popular. Nowadays, the regenerative braking system is part of almost any hybrid or electric car.
So, what is regenerative braking, and how does it work?
Regenerative braking is designed to save energy created by braking and use it to recharge the vehicle's batteries. In older cars, this energy was wasted as it turns into heat and dissipates into the environment.
Even if they use regenerative braking, electric and hybrid vehicles have a traditional braking system. Part of the braking force is assigned to the conventional brake system, while the rest is allocated to energy regeneration.
This decision is managed by the regenerative braking control unit, which figures out if only one or both systems are necessary for safe driving. Additionally, the unit decides if the regenerated energy is stored or used immediately.
Contrary to popular belief, regenerative braking isn't exclusive to hybrid or electric cars. Cars with petrol or diesel engines use the same principle to charge the car battery and save fuel. Nowadays, even electric bikes are advertised as being equipped with regenerative braking.
In a hybrid or electric vehicle, the electric motor can turn in two directions. One of the directions turns the wheels and drives the car while the other recharges the car's battery system.
When you stop pressing the gas pedal, and your car is coasting, or when you press the brake pedal, the engine starts turning in the opposite direction and recovers the energy created by braking.
You can't pinpoint a certain number when it comes to the system's efficiency. The amount of saved energy through regenerative braking is proportional to the level of braking force. So, the system works better at higher speeds and for heavier vehicles.
For electric vehicles, regenerative braking can save up to 75 percent of the energy that would be wasted through conventional braking. For hybrid or classic cars, it can lower fuel consumption by 10 to 20 percent. While it doesn't make a huge difference, it might help you get over your EV range anxiety.
Regenerative braking is less efficient at low speeds, especially during traffic congestion. When driving in slow-moving traffic, you stop the car using a small amount of braking force, so not a lot of energy is available to recharge the car's batteries. It might be worth taking some time and using a travel planning app to avoid heavy traffic, especially if you're low on battery!
When driving a car equipped with regenerative braking for the first time, you might feel the brake pedal is unresponsive or difficult to control for effective and safe braking.
Identifying the transition point between the regenerative and conventional braking system takes some time. So compared to older cars, you'd have to step harder on the pedal if you need to stop your vehicle fast.
However, in modern vehicles, you can select how regenerative braking feels, so you'll feel confident while driving. In addition, you can select the maximum level if you want to recharge your batteries as much as possible, or you can disable it completely if you're not familiar with the car slowing down by itself.
Depending on the car manufacturer, if you lift your foot completely off the accelerator pedal, the car will firmly brake.
This is known as "one-pedal driving" since you only need to control the accelerator pedal instead of constantly switching between the brake and accelerator pedals. The one-pedal driving system, also known as E-pedal, is already available on several electric vehicles such as the Nissan Leaf, Jaguar I-Pace, and Tesla Model S Performance.
Regenerative braking charges the car's batteries and extends the vehicle's range before recharging. So you can drive more for less money. Additionally, because the electric motor does much of the braking, it reduces brake pad and rotor wear.
However, you can't tell for sure how much money regenerative braking is saving. Many factors influence its efficiency, including factors the manufacturer can't anticipate, such as your driving abilities or traffic conditions.
As a system designed to increase a vehicle's range, you can expect it to get better and more and more cars to be equipped with regenerative braking.
Matthew's passions lead him to become a technical writer and blogger. Having a Bachelor's degree in Engineering, he enjoys using his technical knowledge to write informative and useful content.
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