If you’re considering buying a used Tesla, one of the most important things you can do is check the battery health. In an electric vehicle, the battery pack is its heart. A healthy battery means a strong vehicle’s range, efficient charging, and years of reliable use. A weak or degraded battery can mean shorter trips, slower charging, and potentially costly repairs or battery replacement down the road.
At Axio Automotive, we work with Tesla owners and EV buyers every day in Utah and Boise, helping them understand what to look for when shopping for a used EV. This guide will walk you through how to check Tesla battery health, why it matters, and the best tools and metrics to use.
Why Tesla Battery Health Matters
A Tesla battery is designed to last for hundreds of thousands of miles, but no EV battery is immune to battery degradation over time. As you drive and charge your Tesla, the battery’s condition slowly changes, resulting in a capacity loss compared to the original capacity it had when new.
Battery degradation affects:
- Vehicle’s range (you won’t be able to drive as far on a charge).
- Charging speed, especially during fast charging or Supercharging.
- Overall performance and efficiency.
While Tesla battery degradation is generally slow (most owners see only a small drop in battery capacity in the first 50,000 miles), it’s still critical to evaluate before buying. For example, a Tesla Model 3 Long Range that originally had an EPA-rated 353 miles of range might now have 330 miles. That’s about 6.5% degradation, which is normal but worth knowing before you buy.
For more insight into long-term Tesla performance, read our Utah EV Guide: How Many Miles Does a Tesla Last.
Step 1: Check the Displayed Range
One of the simplest ways to gauge Tesla battery health is to check the vehicle’s range displayed on the touchscreen.
Here’s how:
- Fully charge the battery to 100% (or as close as possible).
- Switch the display from percentage to miles in the settings.
- Compare the displayed number to the EPA rating for that model and year.
For example:
- 2021 Tesla Model Y Long Range – EPA range: ~326 miles.
- If the battery check shows 310 miles at 100% charge, that’s about a 4.9% capacity loss.
This method isn’t a perfect battery health test, but it’s a quick way to see if the battery’s condition is within normal limits.
Step 2: Review the Car’s Service and Charging History
How a Tesla has been charged and maintained directly impacts its battery life. Charging habits matter. Frequent fast charging at Supercharging stations can accelerate battery degradation compared to regular Level 2 home charging.
Ask the seller for:
- Tesla service records (accessible in service mode or through the mobile app).
- History of charging methods (home charging vs. Supercharging).
- Any warranty claims or battery replacement.
- Average state of charge (keeping the battery at 20–80% for daily use can help extend battery life).
Step 3: Use Tesla’s Built-in Tools
Tesla gives you built-in ways to monitor battery health metrics.
- Energy App: Shows driving efficiency and real-world range trends.
- Service Mode: Can display detailed battery capacity and state of health (SOH) numbers.
- Tesla App: Syncs your Tesla car to your phone so you can check range and charging status remotely.
Some Tesla owners also use data-logging tools like TeslaFi, which tracks charging habits, software updates, and state of charge over time.
Step 4: Run a Third-Party Battery Health Test
If you want a deeper look, consider tools like:
- Scan My Tesla: Uses an OBD-II adapter to pull advanced battery metrics like kWh remaining, state of health, and temperature data.
- Teslafi or StatsApp: Monitors battery SOH over months of use.
These tools can reveal details about battery pack performance that aren’t visible on the standard display.
Step 5: Understand Tesla’s Battery Warranty
Every new Tesla comes with a warranty, but terms vary by model:
- Model S/X: 8 years or 150,000 miles, with at least 70% battery capacity retention.
- Model 3/Y Long Range & Performance: 8 years or 120,000 miles, with 70% retention.
- Model 3/Y Standard Range: 8 years or 100,000 miles, with 70% retention.
If you’re buying a used Tesla, check if it’s still under battery warranty. If not, a professional battery health test is even more important.
Step 6: Consider Climate Effects in Utah and Boise
In colder climates like Utah and Idaho, you may notice temporary range reduction in winter. This doesn’t always indicate permanent Tesla battery degradation. It’s just the chemistry of lithium-ion batteries in cold weather.
However, extreme heat can cause more lasting effects on battery health. If you’re buying a Tesla from a hot climate, ask about charging habits and parking conditions.
Step 7: Take a Test Drive
A test drive can help you evaluate battery health. During the drive:
- Watch the state of charge drop compared to miles driven.
- Test acceleration and regenerative braking (both can be affected by battery capacity).
- Use the trip meter to check energy consumption in kWh per mile.
If the metrics seem off, it could indicate underlying battery health issues.
Step 8: Compare to Other EVs
If you’ve owned other EVs, you know that not all EV batteries age the same way. Tesla’s thermal management system generally gives it an edge over earlier electric cars, but even Teslas can suffer from capacity loss if poorly maintained.
Step 9: Work with an EV-Savvy Dealer
The easiest way to ensure you’re getting a healthy battery pack is to buy from a dealer experienced in Tesla service and battery checks. At Axio Automotive, we inspect every used EV before it hits the lot, checking for:
- SOH and original capacity.
- Any battery replacement history.
- Charging system function and software updates.
We also guide buyers through the differences between a new Tesla and a well-maintained used one, so you know exactly what you’re getting.
Final Thoughts
By checking displayed range, reviewing charging habits, using built-in tools like the Tesla app, and running a proper battery health test, you can avoid unpleasant surprises.
If you’re ready to shop for a Tesla car or other electric vehicle, stop by one of our Axio Automotive locations in Utah or Boise, or visit us online. We’ll help you find a used EV with the range, performance, and battery health you deserve.
Start your search today at Axio Automotive, or explore our guide on How Many Miles Does a Tesla Last for even more insights.
Check out our 10 locations at Generous Auto, Axio EV, Axio Auto Sandy, Axio Auto Southtowne, Axio Auto Orem, Axio Auto Ogden, Axio Auto Wall Ave, and Southtowne Mitsubishi.
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Pre-Owned Inventory
