Definitive Guide to Electric Car Batteries
Definitive Guide to Electric Car Batteries
The battery was invented by Italian physicist Alessandro Volta in 1800. This remarkable invention has enabled us to power much of our modern world with advanced devices such as laptops, cell phones, satellites, and cars as electric vehicle (EV) adoption continues to accelerate.
Consumers often have concerns about battery life when considering an EV. The thought of replacing a battery pack is particularly daunting considering the average cost is $5,000-$15,000, and that’s not including the cost of labor.
In this article, we will explore how batteries work and how to keep them running optimally.
How Long Do Electric Car Batteries Last?
The battery in your electric car is designed for extended life. However, electric car batteries will slowly begin to lose the amount of energy they can store over time. This phenomenon is called “battery degradation” and can result in reduced energy capacity, range, power and overall efficiency.
Unfortunately, battery degradation is not easy to predict. Not all brands perform the same, and every vehicle is different in how it is driven, charged and maintained. On the bright side, it’s not uncommon for modern EV batteries to last more than 10 years and some will go well beyond that before needing to be replaced.
It’s important to note that battery degradation has been known to worsen in a couple of scenarios:
- If an EV battery is repeatedly driven down close to zero range and then is charged from low to full charge routinely
- If an EV battery is continually charged at Level 3, also known as DC Fast Charging (DCFC)
As such, some automakers suggest limiting DCFC and not making it a primary source of charge. For instance, Kia Motors suggests, “Frequent use of DC Fast Charging can negatively impact battery performance and durability, and Kia recommends minimizing use of DC Fast Charging.” To learn more about charging, read our Definitive Guide to Electric Car Charging.
Environmental factors, such as continued exposure to extreme temperatures, also will impact battery performance and may lead to degradation. In particular, batteries don’t perform very well when the temperature is below 20 degrees Fahrenheit. It’s a good rule of thumb to take your daily driving needs and double them if you live in a cold climate. Make sure any BEVs you’re considering have at least this amount of range – just to be safe.
In sum, it is recommended to keep EVs charged between 60% and 80%, minimize fast charging and avoid extreme temperatures over long periods of time.
Quantifying Battery Degradation
Battery degradation doesn’t happen all at once. On average, EV batteries lose about 1-2% of their range per year depending on the factors discussed earlier. Fortunately, most batteries are designed for durability and will outlast the usable life of a vehicle.
If we look at the Tesla S model battery, researchers have found that traveling 500,000 miles on the original battery should not be a problem. Just because the battery degrades does not mean it is not drivable; it simply loses some of its range and charging efficiency.
In blog posts, Tesla model S owners have noted that approximately 95% of the battery retains its battery function during the first 50,000 miles. A 5% battery degradation could equal 20 miles of range. Oddly enough, the battery only degraded another 5% during the next 100,000 miles. So, 150,000 miles resulted in a total average of 10% total battery degradation. Typically, you wouldn’t need to consider replacing your battery until degradation reaches 50-65%.
Warranty from Automakers
Most automakers have an 8 to 10-year warranty period on their batteries. This is because federal regulation in the U.S. that mandates EV batteries be covered for a minimum of eight years.
However, the terms of the warranty can vary. Some automakers only cover an EV’s battery pack against a complete failure, while automakers like Tesla, Nissan and Volkswagen will honor the warranty if the capacity percentage drops below a specified threshold, typically 60-70%, during the warranty period.
Before purchasing any vehicle, it’s best to check the warranty fine print. For example, the Nissan Leaf has a percentage guarantee of approximately 75%; however, they use their own measurement units represented in “bars.” A full Leaf battery has 12 bars, and the included battery warranty guarantees it for nine bars of charge.
Battery repairs can be expensive, so it is important to understand the exclusions or conditions that can impact the warranty of an EV battery. Some exclusions might include, but are not limited to:
- Use of non-standard charging
- Any damage caused by using or installing non-approved parts
- Using the battery as a stationary power source
- Any damage caused by opening the battery coolant reservoir
- Failing to install software or firmware updates
- Damages or failures caused by repairs performed by non-certified technicians
- Lifting the vehicle from underneath the battery instead of designated body lift points
- Failure to make repairs
- Using vehicle for towing and exceeding load limits
- General abuse or neglect
What about Hybrid batteries?
Hybrid car batteries are similar to EV batteries; they are simply smaller. Since the engine and battery work together in hybrids, if one is not performing optimally, it will impact the other.
Hybrid batteries typically last a vehicle’s lifetime, with modern vehicles routinely reaching 100,000 to 150,000 miles. Accordingly, automakers usually offer a warranty for at least 80,000 miles. In most cases, you can expect to achieve over double that mileage without an issue. Some automakers such as Hyundai even offer lifetime warranties. As a result, if you’re the owner of a hybrid, you likely will never have to worry about replacing the battery.
There is also a time component to battery life — it degrades even if you don’t drive the car long distances. Hybrid batteries are designed to perform for at least 10 years. To cover any unexpected failure, time-based warranties are now standard in the industry. There is a federal mandate for warranties to cover eight years of battery life, so most automakers offer warranties of eight years or more.
If you're faced with replacing a battery on an out-of-warranty car, there's no need to panic. The cost of a new battery pack continues to decline. Some technicians can even install an approved used battery pack salvaged from a wrecked vehicle, which would greatly reduce the potential repair cost.
What Are the Longest-Range Electric Cars?
Battery and range are tightly linked — usually, the bigger the battery, the longer the range. If you’re looking for electric vehicles that can take you the distance, now is a great time to consider one of many long-range options available.
For instance, as of mid-2020, the following battery electric vehicles have the longest range available in the market:
The estimated range for all-electric vehicles continues to increase along with the number of new EVs hitting the road each day. Both battery range and EV adoption have increased rapidly over the last decade. As of around 2010, electric vehicles could barely go above 80 miles on a charge. In contrast, the recently announced Tesla Roadster, for instance, will have a range of over 600 miles!
What Does It Cost to Replace Electric Car Batteries?
As mentioned before, you may not need to replace your EV battery at all. As battery life keeps improving in newer cars, the issue of replacing the battery will become less and less important. In 2019, Tesla announced that it was working on a “million-mile battery” which would likely never need to be replaced.
That said, if you have an older EV, the battery could eventually require replacing.
If your failing battery is under warranty, you should get it repaired or replaced at a manufacturer-approved repair shop. If you request service from a third party who is not approved by the manufacturer, you may void the warranty and expose yourself to substandard workmanship.
If your battery fails outside of the warranty conditions, select dealers and service centers would be able to repair or replace it for you. The cost of repairing/replacing the battery can be broken out into (1) the cost of the replacement battery itself and (2) the cost of the installation.
As the cost of batteries decreases, so does the cost of replacement. The key driver of battery cost is the cost per kilowatt-hour, the unit for energy stored in the battery. Broadly speaking, this cost is in the range of $100 to $300 per kilowatt-hour, depending on the manufacturer. The following price points have been reported recently in 2020:
- Nissan LEAF, 40 kWh battery, ~$5,500, equivalent to ~$137/kWh
- Chevrolet Volt, 16 kWh battery, ~$4,000, equivalent to ~$250/kWh
- Chevrolet Bolt, 66 kWh battery, ~$16,000, equivalent to ~$240/kWh
- Tesla is rumored to be producing their Li-ion batteries at $125/kWh
Installation costs cover the labor and equipment required to install the new battery. From a labor perspective, the work can take 3-5 hours. Altogether, the installation cost can run from $1,000 to $5,000.
After your old battery is removed from the vehicle, it usually enters a second life. Despite having less storage capacity, the battery can still serve a purpose. Old batteries are used in applications that are not nearly as taxing as powering a vehicle. For instance, a battery may be used for stationary storage to support your local utility company’s electric grid.
Let’s explore how EV batteries will continue to add value long after their originally intended use.
Afterlife of EV Batteries
As EV adoption continues to gain momentum, used batteries pose a serious challenge to the environment. What do we do with all the discarded batteries? At the moment, there are two solutions: they can be recycled or repurposed.
Recycling must be handled properly, because toxic chemicals inside can lead to contamination of water and soil. As part of the recycling process, they are smelted to recover the lithium, cobalt, and nickel. However, this can be costly, so re-purposing may be more cost-effective. Many EV batteries still have up to 70% of their capacity left, meaning they can be used for many other energy storage needs.
Automakers are exploring ways to profit from used batteries. In Japan, Nissan has repurposed batteries to power streetlights. In Paris, Renault has batteries backing up elevators. In Michigan, GM is using repurposed batteries from Chevy Volts to back up its data center. They can also be useful for storing solar energy or running electric bikes and other tools. Finding new ways to turn these used batteries into productive solutions will benefit businesses, the environment and consumers.