Tesla Battery Health Test on Model 3 & Y | How Much Have Our Cars Degraded?

Added: 2026-05-13

[00:00:00]Hello guys. In today's video, we are going to  conduct the Tesla Battery Health Test on our cars to see how much they have degraded over the  years. Tesla's high-voltage battery becomes less efficient over time, just like any other. That  is why it is important to monitor your battery health, and Tesla has designed a specific test  you can conduct on your vehicle. Since we have our fleet of S3XY cars available, we are able to test  across multiple models. This includes the base model Y launched at the beginning of 2026, the  2024 Model 3 Highland, and finally the 2019 Model 3 Performance. The base Model Y and the Highland  are equipped with a 60 kWh LFP battery. The 2019 Model 3 Performance comes with a lithium-ion  NCA battery. Before we go through the test, there are certain prerequisites that need to be  met. There should be no active alerts related to the battery or thermal system. Your Tesla should  be in park mode. There should be no scheduled updates or updates in progress. The car should  be at 20% state of charge or less, and it has to be plugged into an AC charger with a minimum of 5  kW of power. As soon as those conditions are met, we can begin the test by going into Controls,  Service, Battery Health Test. Carefully read through the pop-up that appears before proceeding.  Then press Start Test. The motors and climate system will start running as the car begins  to drain its battery to 0% state of charge.

[00:01:38]Then it will recharge it back to 100%. Vehicle  features such as Sentry Mode and climate controls will be disabled. To keep track of the test, a  progress bar and an estimated time remaining will appear on the screen. If you want to see more  videos like this one, make sure to subscribe to our YouTube channel and click the notification  bell. Here are the things to keep in mind while the test is running. Avoid interacting with  your vehicle, for example, by trying to unplug it or tamper with the Tesla app. During the test,  your Tesla may start to produce noise and heat, which is normal. When it's done, the Tesla screen  will display a percentage representing the total energy your battery has retained compared to when  it was new. For example, 83% would mean that your car kept 83% of its capacity. This number accounts  for your Tesla's age and total mileage. Now, here are the results from our tests. For the Highland,  we have 93% of battery health with nearly 40,000 km of mileage. For the 2019 Model 3, we have 83%  with nearly 100,000 km. This number seems too low compared to the average Tesla, but keep in mind  that this car underwent rigorous testing for our products and modifications. And for the base  Model Y, we have 100% battery health, which is no surprise. If you like monitoring car stats such  as this, you can do so via our S3XY app. All you have to do is install our OBD dongle called the  Commander, which draws information from the BMS, and then pair it with the S3XY app. From there,  you can start monitoring car data in real time. In other terms, the Highland has around 7% of battery  degradation in a little over two years. The 2019 Model 3 has 17% of degradation in 7 years, which  is quite impressive, especially considering its age and extensive use. It may seem like a lot, but  for comparison, a 3-year-old Volkswagen ID.3 with 100,000 km on the clock, same as our car, has 23%  of battery degradation. Since we got our Model Y at the beginning of this year, it's expected to  have 0% of degradation. What do you think these results mean for the long-term battery health  of each car? Let us know in the comments below.