Battery health might not be the flashiest Tesla feature, but it’s one of the most important when it comes to long-term ownership.
Good news: Tesla has added a dedicated Battery Health tool that lets owners check degradation, track charging performance, and even adjust your range estimate — all from within the car.
Let’s break down what it is, how it works, and how to use it properly.
What Is Battery Health, and Why Does It Matter?
All electric vehicle (EV) batteries slowly degrade over time. That’s just how batteries work — they go through countless charging and discharging cycles, and each cycle chips away at their maximum capacity.
Tesla measures battery health in simple terms: how much of your battery’s original capacity still remains.
For example:
A battery at 85% health means you’ve lost about 15% of its original capacity. So your Model 3 or Model Y won’t go quite as far on a full charge as it did when it was brand-new — but it’s totally normal.
How Much Battery Degradation Is Normal?
Tesla says its vehicle batteries generally degrade about 15% over 200,000 miles. The first 5% often happens in the first year, as the car’s Battery Management System (BMS) recalibrates to give you a more accurate estimate of range.
Once the BMS settles in, the decline slows dramatically.
Tesla’s Battery Warranty: How Much Is Covered?
Tesla offers an 8-year battery and drivetrain warranty with mileage limits that vary depending on your model:
| Vehicle | Warranty |
|---|---|
| Model S, Model X, Cybertruck | 8 years / 150,000 miles |
| Model 3 RWD / Model Y RWD | 8 years / 100,000 miles |
| All other Model 3 / Model Y | 8 years / 120,000 miles |
If your battery drops below 70% capacity during the warranty period, Tesla will replace it — free of charge.
How to Check Battery Health in a Tesla
Tesla’s built-in Battery Health tool (available in the Service menu) allows you to test and calibrate your battery.
Here’s how to access it:
Go to:
Controls > Service > Battery Health
You’ll see test requirements, the date of your last test, and the estimated health percentage.
Battery Health Test Requirements
To run the test, make sure of the following:
- Your car is in Park
- Battery level is at or below 20%
- The car is connected to the Internet
- No active software updates or thermal alerts
- You’re using an AC charger providing at least 5 kW (Wall Connector or Mobile Connector at 240V/20A)
Total time required: Up to 18 hours, depending on your battery size and charging speed.
What Happens During the Test?
The test runs a full discharge and recharge cycle to help recalibrate your battery’s management system.
Step-by-step:
- Your car discharges battery energy using the heater and motors
- Then it charges back to 100%
- The system logs how much energy was used and updates your range estimate accordingly
Note: You’ll hear fans and systems running — this is totally normal.
Important Tips After the Test
Once complete, your battery will be at 100% charge — not ideal for long periods. Unless you have an LFP battery, Tesla recommends driving your car soon after, or using the climate system to burn some charge.
If you leave it at 100% for too long, it can degrade the battery further.
Where to See Your Results
When the test finishes, you’ll receive a notification in the Tesla app.
To view your results:
Tesla App > Service > Battery Health
You’ll see:
- Date of the test
- Battery health percentage
- A recalibrated range estimate
What If My Battery Health Is Below 70%?
If you’re still under warranty and the result is 70% or lower, contact Tesla support immediately. You may be eligible for a free battery replacement.
How Often Can You Run the Test?
Tesla limits the use of this tool to once every six months unless you access it via Service Mode (not recommended for casual users).
Takeaways: What Every Tesla Owner Should Know
- Battery degradation is normal, especially in the first year.
- Battery Health Tool helps you recalibrate your range and monitor performance.
- Don’t leave your battery at 100% after testing (unless you drive an LFP-based Tesla).
- Use the test tool every 6 months or if your range drops unexpectedly.
In conclusion, Tesla continues to lead the EV world with powerful, owner-friendly tools like this one. The Battery Health tool is simple, smart, and incredibly useful for understanding how your EV is holding up over time — especially if you’re planning to keep your Tesla long-term or monitor warranty coverage.
Have you tried the battery health test yet?
What were your results, and did your range change afterward?
Let us know in the comments below.