With an increase in the number of people riding e-bikes, users are becoming more self-sufficient in terms of managing battery capacity and range – and at some point, that thought experiment shifts to power regeneration and the question of whether electric bikes charge when you pedal.
The popularity of the best electric bikes appears to have created a surge of new energy consciousness among riders, and many questions about everything you need to know about electric bikes and how they work.
Unfortunately, most electric bikes do not come fitted with the technology necessary to power the bike by pedaling. However, some electric bikes do come fitted with this technology, but these are hard to come by, and tend to be a lot more expensive.
Many people believe that all e-bikes will charge themselves while riding.
This is accurate in some aspects for some regenerative electric bikes on the market today, however, due to the low 10% return on input, a person would need to cycle 10 miles to give them a 1-mile charge.
As a result, it is still preferable to use a charger and plug it into a wall outlet.
Most e-bike batteries take around 4 hours to charge and cost about 20 cents, with a range of 30 to 50 miles; in comparison, a regenerative electric bike would require you to ride for 100 miles to get 10 miles back.
Table of Contents
What Is Meant By Regenerative Braking?
Regenerative braking occurs when an electric bike’s braking system and motor collect part of the bike’s kinetic energy and turn it into electricity, which is then utilized to charge the e-battery.
In a normal braking system, the brakes are engaged, causing friction, which causes your bike to slow or stop.
Friction is also produced by the road surface and the surface of the slowing wheel. This friction produces kinetic energy, which is dissipated into the air.
In a nutshell, this heat energy is squandered. Some of this energy is captured through regenerative power, although it is inefficient.
The motor of a regenerative electric bike is used to slow the bike down.
When the user applies the brakes, the controller switches the bike’s electric motor to reverse mode, causing the motor to run backward and slow the bike down.
When the motor is turned backward, it becomes an electrical generator, producing electricity that may be fed back into the battery.
When the controller determines that the motor should be reversed, it will transmit back electrical energy to charge the battery.
The goal of a regenerative braking system is to get the motor to run backward and then use the momentum of the mechanical energy to put the motor in reverse.
Momentum is the feature that keeps the electric bike moving once it has reached the required speed.
When the motor is reversed, the electricity created by the motor is sent directly into the battery, where it can be employed to accelerate and move the bike forward once it has come to a complete stop.
Is Regenerative Braking Good For You?
In principle, you can entirely recharge a battery by pedaling and lightly applying the brakes, but in practice, this is inefficient. To fully recharge a battery, a person would have to pedal for the entire day.
Human cycling for several hours with the added resistance of the brakes will burn many calories and require a large amount of food to recharge the battery.
What you’re doing is transforming mechanical energy (leg energy) into chemical energy, which is then stored in the battery.
Calories are a type of energy, as you may recall from science class. The calories consumed will supply far less electrical power than the energy required to manufacture it, making regenerating a battery ineffective.
The efficiency of regenerative braking can be greatly affected by driving conditions.
If you ride in stop-and-start traffic and brake frequently, you will catch considerably more energy than if you cycled on a long flat stretch without stopping or using the brakes.
If you ride uphill frequently, you will use the brakes less frequently and have fewer opportunities to generate electricity. Variations in motor torque pose another problem for regenerative braking.
Drivers have a habit of varying the amount of braking they apply. As an example, a driver may apply more pressure to the brake as they slow down.
Because regenerative braking must account for torque fluctuations while calculating the amount of energy to recover, this variation in torque produces inefficiency.
However, a regenerative braking system does come with some undeniable benefits. For example, an electric bike fitted with regenerative braking is likely to last a lot longer than a regular bike.
Another advantage of regenerative brakes is that by using the engine to slow your bike and generate power, you are using the brake pads considerably less and thus your brakes will last much longer.
In comparison to usual breaks, this is preferable for most.
The Problems With Regenerative Braking Systems
One disadvantage of regenerative braking systems is that they are not ideal for two-wheel-drive braking systems.
When the regenerative braking system is employed, a negative torque is given to the driving wheel. This negative torque is supplied to only one wheel, and the other wheel is unblocked and free to spin.
Because of the negative torque distribution, you will experience uneven tyre and brake wear. When braking, this could cause sliding.
This is why most e-bikes with regenerative systems have a rear hub motor rather than front hub motors, which are potentially far more dangerous.
Other complications arise as a result of motor torque changes in regenerative braking systems.
In changing driving conditions, drivers frequently change the amount of braking they do. As they slow down, a motorist may apply more pressure to the brakes.
To compute the amount of energy to recuperate, a regenerative braking system must take torque variations into consideration. These torque changes produce further inefficiencies in regenerative braking systems.
In principle, it would be fantastic if you could pedal, charge your battery, and go indefinitely, but reality and science do not support this.
A few manufacturers sell regenerative electric motorcycles, but they are expensive.
With the growing popularity of electric vehicles, we believe they will be trying to increase the effectiveness of regeneration technology, but in the meanwhile, you will only receive roughly 10% of your investment back.