Electric vehicles (EVs) have gained significant popularity in recent years, and one of the primary concerns for potential buyers is the lifespan of the battery. After all, the battery pack is the key component of an EV and can be costly to replace if it fails.
According to Liz Najman, a researcher and climate scientist at Recurrent, a battery and range analytics company, the battery is likely to outlast the vehicle itself. She states, “From everything we’re seeing and for the average vehicle, you can expect the battery to last the life of the vehicle with some degree of degradation in capacity and power.”
When it comes to electric vehicles (EVs), many prospective buyers have a crucial question in mind: How long will the battery last? Undoubtedly, the battery pack is the most vital component of an EV and can be an expensive investment to replace if it fails. In this comprehensive guide, we will delve into the lifespan of electric car batteries, factors affecting their decline, methods to extend their capacity, considerations for used EVs, and the potential for battery replacements.
Understanding the Lifespan of EV Batteries
Electric car batteries are designed to have a lifespan that exceeds the vehicle’s usable life. According to renowned researcher and climate scientist Liz Najman from Recurrent, a leading battery and range analytics company, “The battery is expected to endure throughout the life of the vehicle, albeit with some degradation in capacity and power.”
Factors Affecting EV Battery Decline
Battery degradation is a more critical concern than outright failure. Complete battery failure typically occurs due to manufacturing defects or internal issues. For instance, Chevrolet’s Bolt EV experienced a recall due to battery-related problems. Fortunately, such defects are usually covered by warranties, which often last for at least eight years or 100,000 miles. Some EV manufacturers go a step further by offering warranties that safeguard against both failure and capacity loss. These warranties guarantee a percentage of the battery’s original capability (around 70% to 75%) over the warranty term.
However, understanding the loss of battery capacity and power is a complex matter. The majority of EVs on the road today have been in circulation for less than six years, with nearly 30% sold in 2022. Consequently, we have limited data on long-term degradation. Automakers claim that EV batteries can last up to 20 years, but given the rapid advancements in battery technology, it is challenging to predict their degradation accurately.
EV batteries function by storing and generating energy through the movement of lithium ions and electrons within individual cells. While battery capacity retention is influenced by factors such as usage, charging patterns, and storage conditions, all batteries inevitably experience some degree of capacity loss over time. This natural decline, known as “calendar aging,” serves as the baseline degradation for batteries.
Based on insights from Najman, most EVs initially undergo a higher degradation rate within the first 20,000 miles as the battery stabilizes. However, this decline gradually slows down and levels off. A study conducted on Tesla Model S data by Recurrent estimates a mere 5% decrease in range between 50,000 and 200,000 miles.
Methods to Extend EV Battery Capacity
Although battery degradation is inevitable, EV owners can adopt certain practices to mitigate its impact and extend the overall battery capacity. Here are some expert recommendations from Najman:
1. Opt for Controlled Charging: Limit the usage of fast charging, especially high-voltage options like DC fast charging. These methods generate more heat and stress, which can accelerate battery degradation. Reserve fast charging for when it is truly necessary, such as during long road trips. Opt for regular charging methods for day-to-day needs.
2. Maintain Optimal Charge Levels: Aim to keep the battery charge within the range of 20% to 80%. This range ensures greater stability and longevity for the battery. While charging to 100% is acceptable for occasional long trips, it is advisable not to store the vehicle with a full battery for extended periods.
3. Embrace Partial Charging: Instead of frequently discharging the battery to very low levels, it is more beneficial to recharge the battery from shallower states of charge. For example, instead of going from 80% to 20% in one instance, it is preferable to charge from
Understanding EV Battery Decline
While battery failure is possible, it is usually attributed to manufacturing defects or internal issues with the battery. Manufacturers typically cover these problems under warranty, which is generally valid for at least eight years or 100,000 miles according to federal regulations. Some EV battery warranties also protect against capacity loss, guaranteeing a certain percentage of the original capability (around 70% to 75%) over the warranty period.
However, the concern lies more in battery degradation rather than outright failure. It’s challenging to provide precise answers regarding the loss of battery capacity and power because most EVs have been on the road for less than six years. With rapidly advancing technology, the true degradation of EV batteries over their intended lifespan of up to 20 years is yet to be fully understood.
Battery degradation occurs due to various factors, including usage patterns, charging habits, and storage conditions. All batteries experience a baseline degradation called “calendar aging,” which refers to the natural capacity loss over time. Najman explains that most EVs initially experience higher degradation within the first 20,000 miles as the battery settles, but the rate of decline slows down afterward. For example, based on Recurrent’s analysis of Tesla Model S data, the range may decrease by approximately 5% between 50,000 and 200,000 miles.
Tips to Extend Battery Capacity
While battery degradation is inevitable, there are steps EV owners can take to minimize the impact and extend the battery’s capacity. Here are some recommendations from Najman:
1. Limit fast charging: High-voltage charging, especially DC fast charging, generates more stress and heat, which can accelerate battery degradation. DC fast charging should be reserved for necessary situations, while regular charging methods should be used for day-to-day charging needs.
2. Optimal charge level: Keeping the battery charge between 20% and 80% is ideal for stability and longevity. Although charging to 100% is acceptable for occasional trips, storing an EV with a full battery for an extended period is not recommended.
3. Partial charging: It’s better to charge the battery more frequently from lower charge levels. For instance, instead of going from 80% to 20% in one go, it is preferable to charge from 70% to 40% twice. This practice has a lesser impact on the battery’s health.
4. Temperature considerations: Parking in the shade or a garage during hot weather helps mitigate the negative effects of heat on the battery. Heat can contribute to degradation over time. On the other hand, cold weather might affect the range temporarily but won’t cause long-term damage to the battery.
What About Used EVs?
When considering a used EV, battery health becomes more critical than the mileage reading typically used to evaluate a vehicle’s value. A lower-mileage EV may have a battery with diminished capacity compared to a higher-mileage vehicle.
Najman advises potential buyers of used EVs to obtain a battery health report, which can be provided by companies like Recurrent.