What’s the Price of Replacing an EV Battery?
While you can purchase a pack of batteries for your digital watch for under $10, replacing the 40-kWh pack in a Nissan Leaf can cost you thousands of dollars. Although electric cars entail fewer moving parts and generally lower maintenance costs, the expense of swapping out the battery pack remains a significant challenge for EVs.
lithium battery pack THE MANUFACTURER Fortunately, this issue is expected to diminish in the future as manufacturing enhancements and increased production scale should reduce the cost of replacing an EV’s battery pack. Additionally, the growing global sales of electric vehicles have provided us with a better understanding of the average service life of EV battery packs.
Battery Fundamentals In today’s world, most modern electric vehicles rely on lithium-ion battery packs for energy storage. While other battery types, such as solid-state batteries, are expected to play a role in powering electric cars in the near future, the existing infrastructure for large-scale battery production heavily favors lithium-ion technology.
Lithium-ion batteries offer several advantages
- Higher Energy Density: Lithium-ion batteries outperform conventional lead-acid batteries (common in many traditional cars) and nickel-metal hydride batteries (used in many hybrid vehicles) in terms of energy density.
- Lower Self-Discharge: These batteries discharge at a slower rate when not in use compared to other types.
- Maintenance-Free: Lithium-ion batteries don’t require periodic full discharges or electrolyte maintenance.
- Consistent Voltage: They provide a more consistent voltage output even as their charge degrades.
In simple terms, an electric vehicle equipped with a lithium-ion battery pack can deliver performance akin to a gasoline-powered car with a full tank of gas. Depending on factors like battery capacity, vehicle weight, and aerodynamic efficiency, some EVs can travel hundreds of miles on a single charge. It’s worth noting that an EV’s peak power tends to decrease as its charge level drops, which is why we conduct performance testing with a fully charged battery.
However, lithium-ion batteries do come with some drawbacks:
- Production Costs: These batteries are expensive to manufacture, and the mining of materials like cobalt and nickel, essential for their production, raises environmental and ethical concerns.
- Battery Management: Proper onboard battery management is crucial for ensuring the longevity of lithium-ion batteries.
- Charging and Discharging: Fully charging and discharging lithium-ion batteries repeatedly can reduce their overall lifespan.
- Safety Concerns: While rare, there is a potential risk of lithium-ion batteries overheating and catching fire.
To mitigate these challenges, automakers have developed sophisticated software and hardware solutions to manage battery health and temperature. This includes dedicated cooling and heating systems designed to enhance the efficiency and safety of lithium-ion battery packs, whether they’re powering an EV in the frigid temperatures of Norway or enduring extreme heat in Texas.
How Long is the Lifespan of Electric Car Batteries?
Instead of relying on guesswork, the most straightforward method to gauge the longevity of an electric car battery pack is by referring to the manufacturer’s warranty. Given the substantial cost associated with battery replacement, automakers are cautious not to shoulder this expense due to overestimating the pack’s durability and lifespan. Therefore, the battery’s limited warranty provides valuable insight into the manufacturer’s perspective on the minimum expected lifespan of the battery pack.
Presently, all electric vehicles (EVs) on the market come with a battery warranty that spans at least eight years or 100,000 miles. For instance, Tesla offers an eight-year battery warranty with coverage ranging from 100,000 to 150,000 miles depending on the specific model.
This warranty doesn’t solely address complete battery pack failure; it also serves as a safeguard against significant degradation. With each charging cycle, lithium-ion battery packs experience a slight reduction in their overall capacity. Over time, these incremental decreases in maximum capacity impact the EV’s overall driving range.
For example, Tesla specifies in its warranty that a vehicle like the Model 3 should maintain a minimum of 70 percent of its charge capacity while the battery pack is still under warranty. If the charge capacity falls below this threshold during the warranty period, Tesla commits to addressing and covering the costs associated with this battery-related issue.
Tesla’s threshold is not arbitrary; the likelihood of one of its vehicles’ battery packs degrading to less than 70 percent of its original charge capacity within the warranty period is quite low. A collaborative study conducted by Tesla owners in the Netherlands, utilizing data from Teslas sold worldwide, revealed that Model S sedans experienced an average degradation rate of approximately 5 percent during the first 50,000 miles of driving. This degradation rate becomes even more gradual as additional miles are accumulated. The study indicated that the battery packs of long-range Teslas generally retained at least 90 percent of their original charge after 150,000 miles of driving. In our experience, our long-term Model 3 saw a modest 6 percent reduction in battery capacity after the initial 20,000 miles, after which it remained stable for the subsequent 40,000 miles over two years.
Hyundai offers a similar battery warranty for its award-winning Ioniq 5 electric vehicle, covering 10 years or 100,000 miles. This warranty also encompasses battery degradation, with Hyundai anticipating that the Ioniq 5’s battery pack will lose no more than 30 percent of its original charge during the warranty period.
According to the U.S. Department of Energy, today’s EV batteries are projected to last significantly beyond their warranty period. These battery packs are expected to have a service life ranging between 12 and 15 years when operated in moderate climates. For EVs frequently used in more extreme conditions, the expected service life is between 8 and 12 years.
Safety and Maintenance of Electric Cars
With the exception of low-speed neighborhood electric vehicles, electric cars sold in the United States must adhere to the same safety standards as all other passenger vehicles. Furthermore, electric vehicle (EV) battery packs are required to have a sealed enclosure and must undergo testing under various conditions, including overcharging, extreme temperatures, fires, accidents, water immersion, vibrations, and short-circuiting, as per the Department of Energy (DOE) regulations. EVs also incorporate insulated high-voltage lines and are designed to deactivate their electrical systems in case of a collision or short circuit.
Although electric car fires related to the battery occasionally make headlines due to their unique firefighting challenges, the likelihood of an electric car catching fire is significantly lower than that of a vehicle with an internal combustion engine. In summary, the risk of an electric car catching fire is extremely low, but if such an incident occurs, it typically requires the intervention of the local fire department.
Maintaining an electric car is relatively straightforward. Owners should regularly monitor fluids (coolant, refrigerant, windshield washer fluid), tire condition, and brake pads and rotors. However, the latter components tend to last longer in EVs than in vehicles with internal combustion engines, thanks to regenerative braking, which puts less strain on mechanical braking parts.
Battery Charging Cycles
Similar to how most drivers do not run their internal combustion engine vehicles until they are completely out of fuel, electric vehicle owners typically do not fully deplete their battery packs. Although it is possible to drive an EV to a very low state of charge, most drivers avoid completely draining the battery pack. Given the convenience of home charging, even fewer EV owners are likely to fully discharge their vehicle’s battery pack.
Charging an EV at home may not be the fastest way to increase the state of charge, but it rarely poses an issue due to the longer charging cycles, often occurring overnight. For times when a quick charge is needed, fast chargers are available.
However, these high-speed chargers, while convenient, can accelerate the degradation of lithium-ion batteries compared to slower charging options. To maximize the service life of an EV’s battery pack, it is advisable to avoid unnecessary fast charging. Nonetheless, modern EV batteries can handle occasional fast charges without significant concerns about their impact on the battery’s longevity.
Similarly, it is recommended to avoid charging an EV’s battery to its maximum capacity or allowing it to discharge completely. Many electric cars offer settings to adjust the maximum charge level, with automakers often suggesting charging the pack to 85% or 90% capacity for typical daily use.
Battery Thermal Management Systems
An active thermal management system plays a crucial role in maintaining the peak performance of an electric car’s lithium-ion battery pack. Lithium-ion batteries perform optimally within a temperature range of 50–86 degrees Fahrenheit. Most modern EVs use cooling and heating systems to regulate their battery packs within this temperature range.
Similar to climate control for the vehicle interior, maintaining an EV’s battery pack temperature consumes energy. Consequently, driving range may be slightly reduced in extreme temperatures. However, with these thermal management systems in place, EV battery packs are less likely to experience significantly accelerated degradation in extreme weather conditions.
Inevitably, today’s EV batteries will require replacement in the future. Fortunately, modern EV battery packs are expected to perform reliably for nearly the first decade of use, and possibly even longer. By the time replacement is necessary, manufacturing and material costs are likely to have decreased significantly. While we cannot claim that replacing an EV’s lithium-ion battery pack a decade from now will be inexpensive, it is reasonable to assume that it will be more affordable than today’s costs.