The size of the battery in Plug-In Hybrid Electric Vehicles (PHEVs) significantly influences the efficiency and effectiveness of regenerative braking in several ways:
Impact of Battery Size on Regenerative Braking Efficiency
- Energy Storage Capacity and Recuperation: Larger battery packs provide more energy storage capacity, which means they can accept and store more of the energy recovered during regenerative braking. This results in higher regenerative braking efficiency since more kinetic energy is converted back into stored electrical energy rather than being lost as heat in friction brakes.
- Power and Recharge Rate Limitations: Batteries must handle rapid charging during regenerative braking, which imposes limits on the maximum recharge rate and power. A larger battery typically supports higher power rates and can handle the charge from regenerative braking more effectively without exceeding its limits. Smaller batteries may reach their charge acceptance limits quickly, reducing the amount of energy that can be recuperated and thus lowering regenerative braking efficiency.
- Battery Current and Thermal Constraints: Downsized batteries often operate above their continuous current limits during regenerative braking, which can lead to higher internal resistance losses and decreased efficiency. Larger batteries can maintain operations within optimal current limits, reducing thermal losses and improving overall efficiency.
- Effect on Overall Fuel Economy: The availability of a larger battery allows the vehicle to operate in an electric mode longer and recover more braking energy, which reduces fuel consumption. Conversely, smaller batteries limit regenerative braking effectiveness and electric driving range, increasing fuel use.
- Temperature Sensitivity and Battery Size: Battery performance during regenerative braking is also temperature-dependent. Larger batteries with better thermal management systems maintain efficiency better across temperature ranges, while smaller batteries may experience greater efficiency drops at low temperatures due to higher internal resistance and reduced regenerative braking energy capture.
In summary, larger battery packs in PHEVs improve the efficiency of regenerative braking by enabling higher energy recuperation, supporting greater power and recharge rates, reducing thermal and current-related losses, and enhancing overall fuel economy. Smaller batteries restrict energy capture during braking due to charge acceptance and current limits, leading to less efficient regenerative braking.
This explains why most PHEVs have larger batteries compared to conventional hybrids—to maximize the benefits of regenerative braking and electric driving range.
Original article by NenPower, If reposted, please credit the source: https://nenpower.com/blog/how-does-the-size-of-the-battery-in-phevs-affect-the-efficiency-of-regenerative-braking/
