The battery weight in Plug-in Hybrid Electric Vehicles (PHEVs) significantly impacts their fuel efficiency in several ways:
-
Energy Density and Range:
- While larger batteries increase the electric range of PHEVs, they have a lower energy density compared to liquid fuels. For example, 10 gallons of gasoline contain about 360 kWh of energy and weigh about 28 kg, whereas PHEV batteries may hold 5-30 kWh and weigh between 100-300 kg.
- This means that even after the battery is depleted, the vehicle must continue to carry this weight, which affects overall efficiency.
-
Efficiency Reduction:
- Additional battery weight decreases the vehicle’s efficiency in both electric (all-electric mode) and hybrid (once the battery is depleted) modes. This is because the vehicle must expend more energy to move the extra weight, reducing miles per kWh and miles per gallon.
- In hybrid mode, after the battery is depleted to a certain state of charge (SOC), the engine kicks in, and the weight impacts the efficiency of the engine as well.
-
Structural Support:
- The weight of large batteries requires additional structural support in the vehicle. This structural reinforcement adds to the overall weight of the vehicle, further impacting its efficiency.
-
Operating Conditions:
- Battery performance can also be affected by environmental conditions such as temperature. For example, at lower temperatures, battery efficiency decreases, affecting fuel consumption during blended mode operations.
In summary, while larger batteries provide longer electric ranges, they impose a weight penalty that reduces overall fuel efficiency and increases the energy required for operation. Optimizing battery weight while maintaining necessary capacity is crucial for improving PHEV efficiency.
Original article by NenPower, If reposted, please credit the source: https://nenpower.com/blog/how-does-the-battery-weight-impact-the-fuel-efficiency-of-phevs/
