Battery weight has a significant impact on the overall performance of plug-in hybrid electric vehicles (PHEVs), influencing factors such as energy efficiency, fuel economy, vehicle range, and structural requirements.
Effects of Battery Weight on PHEV Performance
- Range and Energy Storage: Larger batteries increase the electric-only range of a PHEV by providing more energy storage capacity, allowing the vehicle to travel farther on electricity before switching to liquid fuel. This is analogous to how a conventional vehicle with a larger fuel tank can travel farther without refueling. However, PHEV batteries have much lower energy density compared to liquid fuel; for example, 10 gallons of gasoline contains about 360 kWh of energy and adds about 28 kg of weight, whereas PHEV batteries of 3–30 kWh can weigh 30–300 kg plus structural components needed to support the battery.
- Energy Efficiency Impact: Although larger battery capacity extends the all-electric range (AER), the additional battery weight reduces the vehicle’s efficiency both in electric vehicle (EV) mode and hybrid electric vehicle (HEV) mode. Additional weight causes decreased efficiency in miles per kWh in EV mode and miles per gallon in HEV mode once the battery is depleted to the lower state of charge target. The vehicle carries the battery weight throughout operation, even when the battery is depleted, which means the weight penalty continuously affects fuel consumption and efficiency.
- Fuel Economy: Heavier batteries increase the overall vehicle mass, which leads to higher fuel consumption rates when the vehicle operates in hybrid mode. Studies show that while PHEVs consume less gasoline than conventional vehicles and hybrid electric vehicles overall, the incremental weight of the battery increases fuel consumption compared to lighter configurations. Thus, the trade-off between extended electric range and additional battery weight must be balanced to optimize fuel savings.
- Vehicle Structure and Design: Increased battery weight often necessitates additional structural support to safely carry the heavier battery pack, which can further increase vehicle weight and impact performance metrics such as acceleration, handling, and braking.
- Thermal and Power Considerations: Battery power capability and temperature also affect performance; for instance, battery efficiency can decrease with lower temperatures, reducing the effective AER. However, battery power mainly influences regenerative braking and the vehicle’s ability to meet power demands, moderately affecting fuel consumption.
Summary
In summary, the impact of battery weight on PHEV performance is a complex trade-off:
- Larger batteries increase electric driving range and fuel displacement.
- Increased battery weight decreases vehicle efficiency in both electric and hybrid operation modes.
- Additional mass requires structural reinforcements, adding further weight and impacting dynamics.
- Fuel economy benefits from larger batteries are partially offset by penalties from the added weight.
- Environmental conditions and battery design also play roles in performance outcomes.
Optimizing PHEV battery size and weight is critical to balancing range, efficiency, fuel savings, and overall vehicle performance.
Original article by NenPower, If reposted, please credit the source: https://nenpower.com/blog/how-does-battery-weight-impact-the-overall-performance-of-phevs/
