Why regenerative braking is bad for your brake pads

How regenerative braking works

Regenerative braking is engaged by lifting your foot off the “gas” pedal. This reverses the motor, slows down the vehicle, and turns any kinetic energy from braking into electricity for the battery. The EV or hybrid’s friction brakes are not used.

This feature is one reason why EVs and hybrids are much more energy-efficient than gas-powered vehicles. However, the reduced use of the car’s mechanical brakes can cause problems.

How regenerative braking affects brake pads

The regenerative braking system doesn’t replace the traditional braking system altogether. You still “slam on the brake” when you need to stop quickly and forcefully to engage the conventional brakes, However, if you drive mostly in stop-and-go city traffic, where you’ll generally use regenerative braking, you may experience any of the following issues with your vehicle’s mechanical brakes.

Corrosion and rust buildup

In conventional braking systems, constant friction between the pads and rotors keeps the components clean and prevents corrosion and rust buildup. But in vehicles that rely on regenerative braking, this self-cleaning effect is nearly nonexistent. The development of rust and corrosion on the rotors leads to uneven braking performance and potential safety hazards.

If unaddressed, rust buildup may cause rotors to become pitted or warped. This is a costly replacement, particularly common in high humidity regions with frequent precipitation and winter road salt exposure.

Uneven wear and glazing

Glazing occurs where the friction surface of the brake pad hardens and becomes smooth from lack of use. When brake pads glaze over, they’re unable to generate adequate friction, which makes emergency stops and high-speed braking much less effective. Glazed brake pads can cause increased stopping distance and pose a safety risk.

Uneven brake pad wear can occur in vehicles where drivers rely primarily on regenerative braking, but use mechanical braking under heavy loads. This inconsistent use creates pressure imbalances on the brake pads, leading to patchy tire wear patterns and a reduction of braking efficiency.

Brake pad and rotor sticking

Brake pads and rotors can also become stiff or stuck in place over time. Brake drag is where pads remain slightly engaged with the rotor and create unnecessary resistance that can seize brake pads. Brake drag can also result in overheating and uneven brake performance.

Reducing the effects of regenerative braking on brake pads

Regenerative braking presents some challenges in the traditional braking components of a vehicle. There are steps drivers can take to maintain their brake pads, ensuring long-term braking reliability.

Regular inspections and maintenance

Regularly inspecting the condition of brake pads, rotors, and calipers can prevent issues such as corrosion or rust buildup. Checking for signs of rust, glazing, or uneven wear regularly is important for a brake inspection.

Many vehicle manufacturers will recommend having brakes serviced at least once a year. Some things a professional mechanic will do during a regular EV or hybrid brake service include lubricating calipers, cleaning the rotors, and resurfacing or replacing glazed or thinning brake pads where needed.

Intentional use of friction brakes

Because regenerative braking minimizes the need for mechanical brake use, drivers should intentionally use the mechanical brakes from time to time. Occasionally, applying the brake pedal more firmly when stopping rather than allowing regenerative braking to handle deceleration can give your brakes a quick self-cleaning and prevent brake pad and rotor sticking down the road.

Some vehicles will allow drivers to adjust their regenerative braking where necessary. Switching to a low regenerative braking mode from time to time in vehicles with this feature will help mitigate the effects of infrequent mechanical brake usage.

Choosing your brake pads

Some brake pads are better suited to the demands of regenerative braking. Ceramic or rust-resistant brake pads may help extend the lifespan of the braking system and reduce the risks associated with corrosion and glazing. Specialized brake pads designed to resist rust and better perform with regenerative braking systems are available for electric and hybrid vehicles.

Is regenerative braking bad for brake pads?

Regenerative braking offers significant advantages to drivers, especially in helping return some of the charge to the main battery. If not properly managed, though, regenerative braking can lead to corrosion, rusting, glazing, uneven wear, and brake pad or rotor sticking.

Regenerative braking is not inherently bad for brake pads. Drivers can enjoy the benefits of regenerative braking without compromising safety or braking performance by being proactive in their maintenance habits.

If you have questions about your brake pads and how to manage regenerative braking, visit your nearest NexDrive Service Centre to speak with one of our friendly experts.