How to Check Electric Car Battery Health

Key Takeaways

  • Electric vehicles have two batteries: a small 12V battery and a large lithium-ion battery that powers the driveline. Checking the health of the larger battery is important when buying a used EV.
  • Battery health determines the energy storage capacity of an EV and affects its range. Over time, all battery types degrade and lose capacity, resulting in decreased range. However, on average, an EV battery should last longer than you own the vehicle.
  • There are various ways to check EV battery health, such as observing the estimated range on the dashboard, monitoring the state of charge, checking for engine or battery alerts, using diagnostic tools or apps, or visiting a dealer service center. Specific methods vary by manufacturer.

Electric vehicles are rapidly gaining popularity and new models are arriving all the time. As a result, we’re seeing an influx of used EVs available to buy. While that’s great news for potential buyers, it brings some unique new challenges like, instead of making sure the engine runs well, checking the battery health.

If you’re looking for a lightly used and pre-loved EV, there are many things you’ll want to consider before you take out a loan or fork over that hard-earned money. Even though the mileage doesn’t matter quite as much as on a gasoline vehicle, you’ll want to consider how it affects battery life. So, whether you’re looking to buy a used Tesla, Nissan, Rivian, or KIA, or want to check your current vehicle’s health, here’s what you need to know.

Remember: Electric Vehicles Have Two Batteries

Most electric cars have a standard 12V car battery that turns the systems on or off, runs the lights, gauge cluster, and a few other things. We’re not talking about that small battery. In this article, we’re talking about the large lithium-ion (or similar) battery that is essentially the heart of a vehicle. The huge battery pack that powers the electric motors and keeps the wheels spinning.

While the small 12V battery needs replacing every 3–5 years, similar to any other car, the powerful battery for the electric driveline should last far longer, even if it does start to degrade over time. Your EV’s battery is essentially the engine, and it’s as important as changing the oil and keeping that internal combustion engine running and happy.

Why EV Battery Health Is Important

Fast Charge display on the 2023 Chevy Bolt EV
Hannah Stryker / How-To Geek

Electric vehicles require less maintenance than regular cars, but that doesn’t mean it’s all sunshine and rainbows. You’ll still need to keep up with several different things. If you’re buying a used EV, the most important factor is the battery system.

A simple way of looking at it is the battery’s health and capacity will determine how much energy it can store to power your vehicle. A healthy battery will offer more range to drivers, almost like miles per gallon and how far you can go on a full tank of gas. Over time, all battery types will degrade and lose a little capacity, meaning an EV will eventually get less range than it did when it was new.

Tesla claims that after 100,000 miles, battery health remains at around 90% or more, meaning you’ll still have plenty of capacity. For example, on an older Model X with 150K miles, the estimated range of 348 miles per charge could drop around 10-15%, meaning a full charge only gets about 300 miles of range. That’s because the battery experienced some natural degradation and now has a slightly lower capacity. At that point, it doesn’t need to be replaced; it just won’t charge to 100%, which is perfectly normal.

Don’t worry, though. On average, an electric car battery should last longer than you own the vehicle, and most come with an 8-year warranty from manufacturers in the United States.

How to Test Your EV Battery Health

Now that you understand how important battery health is for an electric car, truck, or SUV, you’ll want to check it when buying a used vehicle. Thankfully, there are several ways to do it on various models. The easiest way to check battery health on any EV is to look at the dashboard. However, taking things further with vehicle-specific tools we’ll mention below is probably a good idea.

  • Check overall range estimates: Fully charge the battery and then check the estimated range on the dash. If that lines up with the manufacturer’s estimated range, you’re in good shape.
  • State of Charge (SOC): The dash or infotainment display will show you the state of charge or remaining battery percentage as you drive. If this drops an abnormal amount during casual city driving, it could be a sign of a bigger issue. Keep in mind that estimates aren’t always accurate, but this is one more quick way to gauge the situation.
  • Check Engine Lights (or Battery): No one wants to see a CEL while driving, and on an EV, it’s even worse if you get an alert on the dash from the battery management system (BMS). Check the owner’s manual for more details if you see a light you don’t understand.
  • Diagnostic Tools and Apps: Most companion apps (from Tesla to Hyundai) have tools that let users check battery health. Any honest 3rd party seller will show you the vehicle battery stats. You can even access select battery health information from Tesla’s infotainment display in the service menu.
  • Dealer Tools and OBD-2 scanners: Additionally, you could always request bringing the vehicle to a dealer service center to complete a battery test. I’d recommend it on any large purchase, like taking a used car to a mechanic before buying. Savvy DIY buyers could even use their own OBD-2 scanner.

While these aren’t the only ways to check battery health on an EV, they’re some of the quickest and most accessible options. Then, below are a few more details specific to several vehicle manufacturers that might help you pick the right vehicle.

How to Check the Battery Health on a Tesla

Front trunk open on a Tesla Model 3.
Hannah Stryker / How-To Geek

The quickest way to check the health of a Tesla battery is by viewing the available range when the battery is full. Then, if available, go into the settings menu and unlock “service mode” as demonstrated on YouTube to run a battery health check. Unfortunately, it takes a while for an accurate reading, so perhaps ask a seller to perform the test and share the results before you meet up for a test drive.

Furthermore, the Tesla app has a generic (but still useful) battery and overall vehicle health options menu, which shares valuable information. Additionally, several popular 3rd party apps, like Tessie, will show battery health, degradation, and tons of other details. Tessie is a great way to keep tabs or conduct due diligence on a Tesla.

How to Check Nissan Leaf Battery Information

Nissan Leaf EV Charging

Another popular EV showing signs of age is the Nissan Leaf. Again, most EVs have all sorts of battery information in the companion apps, dashboard, or accessible from the infotainment display. For example, the Leaf and Ariya both have helpful battery stats at a glance. Specific generation Leaf models will show up to 12 bars on the display for battery health, which indicates whether the battery is truly full or is dealing with some degradation. Navigate to the battery capacity section using the steering wheel controls and take a look. You’ll want to do this when you first test the vehicle and check again once it’s fully charged.

Then, several third-party apps can communicate with an ODB-2 dongle and share helpful insights. A prime example is Leaf Spy Pro (Android and iOS), which can access all sorts of crucial metrics regarding your vehicle.

How to Check the Battery Health on a Rivian

Rivian R1S plugged into a charging cable
Tyler Hayes / How-To Geek

Rivian vehicles are still relatively new, but some R1T owners are coming up on the two-year mark and have put on plenty of miles. Rivian doesn’t have an easy tool to check for overall battery health, but you can still get a somewhat accurate gauge by fully charging the vehicle and checking the estimated range. The dash screen will share information on battery charging, estimated range, SoC, and more during the charging process. Remember that those numbers fluctuate based on driving habits, temperatures, and more, so checking when the battery is full yields the best results.

You can download third-party apps and use an ODB-2 dongle, take the vehicle to a Rivian service center, or do some rough calculations yourself. Realistically, any new car will experience some battery degradation during the first year or so, similar to a smartphone, then flatten out and continue to offer excellent range and overall usage.

How to Check the Battery Health on a Ford EV

Charging port of the Ford F-150 Lightning Flash.

If you’re the proud owner of a Ford Mustang Mach-E or F-150 Lightning, you’re probably also wondering about battery health. Whether it’s for your own personal peace of mind or you’re getting ready to sell it, having battery information may help. Like any other model, using the onboard displays to calculate information on a full charge is somewhat reliable.

Another option is the FordPass app, which can share valuable battery stats with owners. Recurrent is a popular third-party service and tracker, or you can always get an OBD-2 scanner and try apps like Batt-Scan, CarScanner, or FORSCAN. However, as with any vehicle, your best bet is to take it to a dealership or service center for the most accurate results.

EV Battery Packs Are Pretty Reliable

With how new electric vehicles are, there are understandably a lot of questions or unknowns. In general, most experts suggest that an EV battery can easily last 15—20 years. Then, even after that long, they don’t stop working; you’ll just get less range from a “full” charge. This is similar to how an old gasoline vehicle gets fewer MPG the older it gets. Don’t overthink it, but certainly ask questions about the battery while going for a test drive and inquiring about a potential purchase.

Battery health shouldn’t be a huge concern unless you’re buying an old or heavily used EV with over 150,000 miles. Again, all manufacturers in the U.S. offer at least an 8-year warranty, and the battery can undoubtedly last longer than that. In fact, there’s a good chance the battery will last longer than you own the vehicle.

Use some of the many tools, apps, or in-vehicle information to make an informed decision, then follow some common tips to extend its battery life. Now, all that’s left is to enjoy your new-to-you electric vehicle.


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