The GMC Hummer EV is a vehicle known for its impressive performance and features, including its massive battery pack. The engineering consultancy firm Munro & Associates recently conducted a teardown of the Hummer EV battery to gain insights into its design and construction.
Key features of the GMC Hummer EV’s Ultium battery system include:
- Large capacity of 246 kWh is one of the highest in the world.
- Steel case that is made up of 139 individual stamped steel components.
- Spot-welded construction with over 3500 welds.
- Usable capacity of 212 kWh, which is still enough to provide the Hummer EV with 329 miles of range.
- Weight of over 2800 pounds is about as much as a Subaru BRZ.
- Inefficiency comes as Hummer is a 9000-plus pound machine driving around on 35-inch tires.
- A design that is not trying to be a mass-market commuter but rather to prove out the technology and to prove to the world that the technology is robust enough to buy that $45,000 commuter and not worry that it’ll crap out in two years.
One notable aspect of the battery pack is its casing, made of stamped steel components instead of the lightweight aluminium extrusions commonly used in other electric vehicles. Critics have raised concerns about the weight and cost of using steel instead of aluminium.
Aluminium cases
Munro’s team suggests GM’s decision might be influenced by Ford’s use of aluminium cases and composite battery tray covers in its electric vehicles. They speculate that the availability of aluminium for such cases might have been limited due to Ford’s production needs, leading GM to explore alternative options.
Steel Components
Using stamped steel components offers GM flexibility in manufacturing, as these parts can be produced using either high-tonnage or low-tonnage presses. The case design is also repeated throughout, simplifying component manufacturing. Munro’s team believes that steel has certain advantages, particularly for an off-road vehicle like the Hummer EV, as it can provide better properties and potentially result in a lighter overall design than aluminium.
The size of the Hummer EV’s battery pack has also drawn attention. It consists of 24 modules of pouch cells, totalling 246 kWh, with 212 kWh of usable capacity. This high capacity gives the Hummer EV one of the highest ratings in the world. However, its efficiency is lower than other electric vehicles, partly due to the vehicle’s weight and the battery’s contribution. The battery pack alone weighs over 2800 pounds, which raises questions about the environmental impact of such large and heavy electric vehicles.
Portability
Munro’s team acknowledges there may be areas where GM can improve profitability in the battery pack. Other teardowns of Ultium batteries used in other GM models, such as the Cadillac Lyriq and Chevrolet Equinox EV, could reveal shared components and potential cost-saving measures.
While the Hummer EV’s Ultium battery system has its strengths, it is not considered the most efficient or cost-effective design in the market. For example, Tesla’s 4680 battery pack is recognised as highly efficient. However, reducing the cell count in a battery pack can be a cost-saving measure, as each kilowatt-hour of capacity currently comes with a significant price tag for automakers.
Pros of the GMC Hummer EV:
- Impressive performance: The Hummer EV offers outstanding performance metrics, including a high-capacity battery pack, powerful electric motors, and excellent off-road capabilities. It can tow heavy loads and has a long driving range.
- Cutting-edge technology: The Hummer EV incorporates advanced technology and features as an electric vehicle. It showcases GM’s Ultium battery system and benefits from the latest developments in electric propulsion technology.
- Bold design: The Hummer EV stands out with its rugged and aggressive design, making a statement on the road. It retains some iconic Hummer design elements while incorporating modern touches.
- Enhanced sustainability: By being fully electric, the Hummer EV contributes to reducing greenhouse gas emissions and dependence on fossil fuels. It aligns with the global shift towards sustainable transportation and promotes environmental consciousness.
- Showcasing EV capabilities: The Hummer EV is a flagship model for GM’s electric vehicle lineup, demonstrating the potential and capabilities of electric vehicles to the general public. It helps break the stigma surrounding electric vehicles and promotes their adoption.
Cons of the GMC Hummer EV:
- High cost: The Hummer EV is a luxury electric vehicle with a high price tag. Its premium features, performance, and large battery pack contribute to its elevated cost, making it less accessible to the average consumer.
- Heavy and inefficient: The Hummer EV’s size and weight and large battery pack make it less energy-efficient than smaller and lighter electric vehicles. Its energy consumption per mile is higher, resulting in lower MPGe (miles per gallon equivalent) ratings.
- Environmental impact: Despite being an electric vehicle, the Hummer EV’s substantial weight and use of resources for manufacturing raise concerns about its overall environmental impact. The production and disposal of such large and heavy vehicles can have a significant ecological footprint.
- Limited availability: Initially, the Hummer EV may have limited availability due to its premium positioning and production constraints. It might take some time before it becomes more widely accessible to customers.
- Competition and alternative options: The electric vehicle market is rapidly evolving, and several competing models are available. Some competitors may offer better efficiency, lower costs, or different features, making the Hummer EV less appealing to certain consumers.
Conclusion
The GMC Hummer EV showcases the capabilities of GM’s electric vehicle technology. Despite potential efficiency and cost concerns, the Hummer EV serves as a statement vehicle for GM’s electric ambitions. As GM expands its electric vehicle lineup, optimising efficiency and reducing costs will be crucial to offering affordable electric vehicles to a wider audience.
