Regenerative Braking Calculator
Calculate energy recovery during braking for electric vehicles
Formula
Kinetic Energy:
$$KE = \frac{1}{2} m (v_i^2 - v_f^2)$$
Energy Recovered:
$$E_{recovered} = KE \times \eta_{regen} \times \eta_{motor}$$
Range Added:
$$Range = \frac{E_{recovered}}{Consumption}$$
About this Calculator
Calculate how much energy your electric vehicle can recover during braking. Regenerative braking converts kinetic energy back into electrical energy stored in the battery, extending your driving range. This calculator accounts for regen system efficiency and motor/inverter losses.
How to Use
- Enter your vehicle's total mass including passengers and cargo
- Set the initial speed before braking (typical highway: 100-120 km/h)
- Set the final speed after braking (0 for complete stop)
- Adjust regen efficiency (how much of braking is regenerative vs friction)
- Set motor/inverter efficiency (typically 88-95% for modern systems)
- Enter your vehicle's energy consumption rate
- View the energy recovered and equivalent range added
Frequently Asked Questions
What is typical regen efficiency?
Most EVs capture 60-80% of braking energy through regeneration. The rest is lost to friction brakes, aerodynamic drag, and tire rolling resistance. Efficiency varies with braking intensity - gentle braking allows more regen.
Why can't EVs recover 100% of kinetic energy?
Losses occur at multiple stages: motor generator efficiency (~90-95%), power electronics (~95-98%), battery charging (~90-95%), and some energy goes to friction brakes for safety. Total system efficiency is typically 60-75%.
How much range does regen add in real driving?
In city driving with frequent stops, regen can add 10-20% to your range. Highway driving with few stops sees minimal benefit. Mountainous terrain with long descents can recover significant energy.
