The rapid rise of electric vehicles (EVs) is challenging the strides made by automakers over the past decade in shedding vehicle weight, resulting in potential safety concerns and environmental implications. The proliferation of EVs has led to significant increases in curb weights, largely due to the substantial battery packs required for extended range. These heavy batteries have caused the average curb weight of EVs to exceed that of traditional internal combustion engine vehicles by 20 to 30%. The introduction of large and weighty battery packs, like the 2,818-pound battery in the GMC Hummer EV, has almost nullified the lightweighting progress achieved in the past years. In total, the GMC Hummer EV tips the scale at 9,093 pounds.
The weight gain in EVs poses multiple issues. Firstly, the extra mass puts other road users at a greater risk in case of collisions. Studies suggest that an additional 1,000 pounds in vehicle weight can increase the likelihood of crash fatalities by as much as 47%. Secondly, the added weight limits the driving range of EVs and affects overall energy efficiency. Despite the deceptive sensation of lightness due to powerful electric motors, the added mass is detrimental to both performance and efficiency. Moreover, the substantial curb weight has led to the shedding of tiny rubber particles from tires, increasing pollution concerns.
EVs are also burdened by the inclusion of advanced electronic systems required for automated-driving features, which contribute to the overall weight increase. Safety concerns have led to over-engineering, and the integration of safety features further adds to the weight. Even though EVs are incorporating lightweight materials like aluminum and carbon fiber, the substantial battery packs and additional electronic components are offsetting any potential weight reductions.
Vehicle carriers are even forced to limit the number of EVs that they transport at one time due to the weight constraints, in addition to spending money to reinforce some of their carrier trailer equipment.
Efforts to reduce EV weight face challenges, as the unique design constraints of electric vehicles limit opportunities for traditional weight-saving strategies. The complexity of battery technology and the need to ensure crashworthiness pose significant obstacles. While advancements in battery chemistry and packaging could lead to weight reduction, experts acknowledge that achieving substantial improvements may require fundamental changes to battery cell arrangement and enclosure design. Innovations like lithium iron phosphate cells and structural cell-to-pack configurations are being explored to address both safety and weight concerns.
The rapid weight increase caused by the incorporation of heavy battery packs and safety features in electric vehicles has reversed the weight-saving progress achieved by automakers over the past decade. This weight gain not only poses safety risks for road users but also impacts vehicle efficiency and contributes to pollution. Overcoming these challenges and achieving meaningful weight reductions will require innovative approaches to battery design, materials, and vehicle architecture, all while balancing safety and performance considerations. As the electric vehicle industry continues to evolve, addressing these weight-related challenges will be a crucial aspect of ensuring the long-term sustainability and viability of electric transportation.
Source: AutoNews (subscription required)
