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Tesla Batteries Last Forever (Basically)

By Paul, Aug 2 2017 03:37PM

Published on July 28, 2017Featured in: Automotive, Big Data, Green Business, Oil & Energy

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Ben Sullins

Ben Sullins

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Data Geek at Teslanomics

New data suggests Tesla batteries last up to 25 years. In this episode, we’ll be diving into this data and seeing how it translates to owners.





Back in April, I shared data on Tesla battery degradation. Since then, Tesla owners have been measuring and sharing their battery degradation data – and the results have been surprising. Tesla owners who contributed to this data first drained their EV batteries down to 0%, then charged fully them to 100%. This is to get a consistent measurement on how much energy a battery can hold.


Despite the data, many people wonder why lithium-ion batteries in phones and laptops can barely hold a charge after a few years, while lithium-ion EV batteries don’t suffer the same fate. Well, according to lithium-ion battery cells studies, after 500-800 charging cycles and 100,000 to 150.000 miles a battery’s charging capacity drops to around 70%. However, most EV owners don’t typical drain their batteries to 0% or 100%. This increases the battery life significantly. Based on study estimates, owners who practice partial charging generally see degradation after 1,200-1,500 charging cycles and 350,000 miles of life.


Because study data on EV battery life is limited, the data provided by real owners, as mentioned above, is much more valuable. It is important to note, charging habits are not the only contributing factors to battery life as factors like temperature and usage patterns also play a role.


As stated, most owners don’t typically run their batteries to 0%, and by default, a Tesla battery stops charging at 80%. This is to reduce battery strain.To even further reduce battery strain, Tesla may limit Fast Charging speeds. All of these factors combined are Tesla’s safeguard to help protect your vehicle, ensure you have a great experience with your luxury EV as well as allow for an expansive lifespan (unlike phone and laptop batteries).


In running some regression analysis on the user-provided data, I found that there was some high volatility. This is likely due to the factor that the data is user-reported, and it is not being measured in a controlled environment.


When Eindhoven University of Technology Systems and Control Professor, Maarten Steinbuch, looked at this data, he found that “on average the batteries have 92% remaining at 240.000 km. If the linear behavior would continue, then the ‘lifetime’ (still 80% capacity left) can be calculated as follows: 92-80 = 12% times 45,000 km = 540,000 km.”


I also looked at another studied from YouTuber and battery aficionado Jehu Garcia. He tested some early Tesla batteries and found that without use, batteries degraded at about .35% per year. Which means, after about 285 years, these batteries will be almost completely dead.


Working with the figure that batteries will retain more than 80% of their capacities for up 310,000 miles and considering that the average US drives about 13,5000 miles, on average, a Tesla battery does not need replacing for around 23 years. This is:


15 more years after the battery warranty runs out


13 years after cars become fully autonomous


4 years after my son can legally drink


and 10 years after the robots take over our world and enslave humanity


Okay, that last one might come sooner, we’ll see…


The point is, by the time your Tesla battery wears out, we’ll be in a totally new world - and likely won’t even be driving ourselves anymore. In fact, Elon Musk recently stated that he thinks in 20 years we won’t even have steering wheels in cars.


So, when it comes to the lifespan of your Tesla battery, rest easy. It will likely outlast the rest of your car.


I compiled my data using the following sources:


https://steinbuch.wordpress.com/2015/01/24/tesla-model-s-battery-degradation-data/


https://www.fhwa.dot.gov/ohim/onh00/bar8.htm


As always, for the latest Tesla news, visit us at Teslanomics.co – and sign-up for our email updates or subscribe on YouTube


Ben Sullins is the host of the weekly show Teslanomics and a Linkedin Learning instructor. You can check out Ben's latest course here: Hadoop for Data Science Tips, Tricks, & Techniques


Ben has nearly 20 years of experience in the field of data science and loves to use his skills to explore technologies changing our world. You can find Ben on twitter at @teslanomicsco

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