John Goreham - - One concern many battery-electric vehicle owners have is that the high-voltage traction battery in their vehicle will lose its effectiveness over time. This means that the range is reduced. Tesla allows many owners to test their vehicle’s battery. It’s a handy feature. One owner who put their 2022 Tesla Model Y to the test was owner M.A., who posted this in a Tesla club online. I did a battery test on my 2022 Tesla Model Y Performance on the service center charger since I had a 48 hour test drive on the new Model Y. 81% at 46k miles. Is this result good or bad? Tesla says that the high-voltage Battery in Model Y is designed to perform well over the entire lifetime of the vehicle. However, Tesla also says that the battery becomes less effective over time due to aging and usage. This is because the energy retention of the Battery depends on a number of factors such as age, the battery size of the pack, and its specific chemistry, as well as how you drive and charge your vehicle. Every EV owner knows that frequent DC charging is a particular threat to battery health. The Tesla Model Y Performance had an EPA-estimated range of 303 miles in 2022. Therefore, if the battery is now at 81% health, it means that the range may have been reduced a bit, perhaps to about 245 miles. How the operator drives the vehicle, the speeds, and the temperature will all impact the range estimate. Tires could make the biggest difference if the vehicle’s original tires have been changed to new tire models. In any case, the battery is no longer at its maximum after having provided 46,000 miles of service. The Results And The Opinion Of Fellow Owners Fellow owners chimed in to help M.A. come to grips with the battery pack test results. Here is what a few fellow owners said in reply to M.A.’s request for feedback. First, let’s hear from owners who say this is nothing to be concerned about: -M.W. - Normal. -S.L - It's really bad... It should reach that after 6-8 years and 150k miles. -D.W. - You’re gonna get a replacement pack at that rate. -B.H - If you get down to 69%, you win a new one under warranty. Clearly, different owners see this result differently. There is no consensus. However, Tesla’s Model Y Performance warranty is very clear. Here is the Tesla Model Y Performance battery warranty: 8 years or 120,000 miles, whichever comes first, with a minimum 70% retention of Battery capacity over the warranty period. As you can see, D.W. and B.H. are correct. It seems as if this battery is pointed toward a warranty replacement if the degradation continues at the same rate it has been. However, that may not be what happens. The battery could slow its rate of degradation, or pause it for a duration of many miles. For example, MindSeeker on Reddit says, “10% degradation over 3 is very normal. Most users have about 5% degradation in this first year. Degradation slows down after the first few years.” Similarly, the website Tesla-Info says this: Reports suggest there is an initial drop within the first few months, and then the rate of degeneration tails off. A typical scenario is therefore a 5% drop fairly quickly and then a further 5% drop over the life of the car. If your car has between 5% and 10% degradation, a higher figure on older cars, it's quite normal. How To Test Your Tesla Battery If you own a Tesla, you can test your battery health yourself. Budget a full day for the test. It can take up to 24 hours to get a result. Also, plan for your battery to be empty when the test is complete. That means you will need to plan for time to recharge before driving. To start the test, your Model Y has to be plugged into an AC charger (not a Supercharger or DC charger) that provides at least 5 kW of power. Most Level 2 chargers, like the NACS Emporia charger shown in our top-of-page image, offer about double that rate of power (40 amps x 240 volts = 9,600 kW). You cannot use a mobile charger and 120-volt power. The next step is to meet the following conditions for testing: There are no active alerts related to the Battery or thermal system. 1) Model Y is in Park. 2) There are no pending software updates. 3) There is less than 20% Battery level remaining. Once you are all ready, do the following: Plug in your vehicle to the proper AC charger. Touch Controls > Service > Battery Health Test. Read the popup, then touch Start Test. While the test runs, stay off your Tesla App and don’t unplug the car during the test. Tesla says that when the test is running, your Model Y may produce heat and loud noises. You may hear the fan running at high speed. This is not a cause for concern, but rather normal and expected. At the completion of the battery test, your Model Y will display the percentage representing a comparison of your battery's energy retention to when it was new. If you own a Tesla Model Y, have you performed a battery test? Please tell us about your experience in the comments. It may help other owners. Also, do you think J.M. will end up with a replacement battery, or will the one he has stay above 70%? Image of Tesla Model Y Performance on Level 2 Emporia Charger undergoing battery test by John Goreham. John Goreham is a long-standing member of the New England Motor Press Association and an expert vehicle tester. John completed an engineering program with a focus on electric vehicles, followed by two decades of work in high-tech, biopharma, and the automotive supply chain before becoming a news contributor. He is a member of the Society of Automotive Engineers (SAE int). In addition to his eleven years of work at Torque News, John has published thousands of articles and reviews at American news outlets. He is known for offering unfiltered opinions on vehicle topics. You can connect with John on LinkedIn and follow his work on his personal X channel or on our X channel. Please note that stories carrying John's by-line are never AI-generated, but he does employ grammar and punctuation software when proofreading and he also uses image generation tools.