Definitive Guide to Electric Car Batteries

Definitive Guide to Electric Car Batteries

An electric battery is basically a device that stores chemical energy that is converted into electricity. The modern electric 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, smart phones, satellites, and even electric cars.

Consumers often have concerns about battery life when considering purchasing an electric car (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’ll explore how batteries work and how to keep them running optimally.

Table of Contents

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. The average EV owner will sell their car long before they would need to replace the battery pack.

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, please visit the section on Electric Car Charging.

Environmental factors, such as continued exposure to extreme temperatures, 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. When it’s really cold and you’re using the car’s heater, your range can temporarily drop by as much as 40%.

To maintain a battery pack at peak performance, it is recommended to keep EVs charged to between 60% and 80%, minimize fast charging and avoid extreme temperatures over long periods of time.

The Truth About Battery Degradation

Battery degradation doesn’t happen all at once. On average, today's electric car batteries only lose about 1-2% of their range per year. New EV batteries are designed for durability and will outlast the usable life of a vehicle.

What You Need to Know

Thanks to lithium-ion batteries, we all enjoy the ability to recharge everything from smartphones and laptops, to the latest electric cars. Degradation over time means that the battery pack will lose some of its ability to hold a charge over time. There are a few things that you need to know about extending the life of your battery that will keep it in good condition for the long haul. First and foremost, you should never "over charge" them.

When keeping an electric car charged, it is best to only charge them to 80% of the battery's capacity. Likewise, don't run a battery down all the way to zero as that can damage them. Overcharging is the number one reason that battery packs degrade quicker. Another thing to remember is that EV batteries hate to be frozen. It's best to keep electric cars in the garage in winter months when outside temperature are in the sub-freezing zone.

The biggest take away we want you to get from this article is that EV battery degradation is really nothing to worry about. 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%.

What's Coming

A new generation of lithium-ion electric car batteries are on the horizon that could last millions of miles. Another solution for battery degradation is new technology known as the Solid-State battery that is reported to offer enormous capacity. We're talking EVs with a driving range of over 1,000 miles and recharge times of just five minutes.

In the meantime, battery degradation in today's battery electric cars is really nothing to concern yourself with. Automakers typically offer battery warranties for eight years or 100,000 miles on new cars. Plus, battery degradation is a very slow process and it is very likely that you will sell or trade your EV in long before loss of battery function becomes a problem. According to a recent survey, the average EV owner only notices a 2% battery decline after three years of driving and a 7% decline after six years on the road.

Electric Car Warranties and Exclusions

Warranties from Automakers

Most automakers have an 8 to 10-year or 100,000 miles warranty period on their batteries. This is because federal regulation in the U.S. mandates that electric car 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.

Warranty Exclusions

Battery repairs can be expensive, so it is important to understand the exclusions or conditions that can impact the warranty of an electric car 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

Hybrid Battery Warranties

Hybrid car batteries are similar to EV batteries; they are simply smaller. Since the gasoline engine, electric motor 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 or much more. 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’ll likely 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 hybrid car 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.

Cost to Replace Electric Car Batteries

As mentioned before, you may not need to replace your electric car 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 electric car, the battery could eventually require replacing.

Experiencing Battery Failure

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.

Cost of Replacement

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. 

A Second Life

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 useful 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 electric car batteries will continue to add value long after their originally intended use.

Afterlife of Electric Car Batteries

As electric car 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 old batteries 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 the repurposing of used batteries 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. VW recently opened its electric car battery recycling plant in Germany that can recycle 3,600 battery systems per year. Repurposed EV batteries 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.

Next, spend some time learning everything there is to know about charging electric cars by reading our Definitive Guide to Charging Electric Cars.