Numerous myths circulate about electric vehicles. One of them pertains to battery longevity being no better than your average smartphone; where a single charge will last you a day and a bit when you first unbox it, but within a year you’re carrying around extra cables and power banks, and receiving counselling for phone-charge anxiety.
It is not incorrect to say that EV batteries degrade. They do. But is it correct to say that within a few thousand kilometres a brand-new Battery Electric Vehicle is essentially as useful as an old iPhone?
Not quite. In fact, recent research and real-world data have shown that these worries are largely unfounded. Depending on how and where they are used and charged, modern EV batteries are not only durable but also capable of providing reliable performance over extended periods.
Recurrent, an organisation that has tracked battery replacements, revealed that only about 13% of early EV models (pre-2015) required battery replacements. For newer models (2016 and later), the replacement rate drops to under 1%.
EV batteries follow an S-shaped degradation curve: initial noticeable degradation, a long period of slow linear ageing, and then a sharp decline at the end of life. This slow degradation period allows most EVs to maintain a high percentage of their original capacity for many years.
This is good news when replacing the battery on an EV can cost over $20,000. Although keep in mind that virtually all modern EVs come with an 8-year, 160,000km battery warranty, which covers battery capacity dipping below 70%.
Leafing through 15 Years of Real-World Data
Fortunately, some EVs have been on sale for nearly 15 years now, so there is real-world data to draw on. One study by Recurrent, based on researching 15,000 EVs in the US, revealed that most EV batteries retain about 90% of their original range after 160,000km. The report suggested that battery life was actually 15-20 years and would outlast the vehicle itself.
The Nissan Leaf is one of the earliest mainstream success stories in the EV sphere produced since 2010. The original battery packs are now coming up to 14-15 years old. Earlier models (2011-2014) experienced higher rates of battery degradation. A new ‘Lizard’ battery was introduced in 2014 to remedy this.
While Nissan initially expected batteries to retain 80% capacity after five years and 70% after 10 years, the company claims that real-world experience has shown the batteries outperformed those expectations with at least 75% capacity retained over a decade. Nissan claims that almost all Leaf batteries produced are still in use.
Toyota’s new 2023 bZ4X will retain 90% of its battery capacity after 10 years or 240,000km, says the company.
BMW i3 and Tesla Model S
The BMW i3 was introduced in 2014 in all-electric and range-extended hybrid guises. The original 22kWh battery showed notable degradation with some owners reporting as much as 20% lost after 45,000km. However, the 33kWh battery from 2017 was significantly improved.
Teslas have been reported to experience 2.3% degradation per year at most. According to Tesla’s 2022 Impact Report, the Model S (introduced in 2012) retains up to 88% of its battery capacity even after approximately 320,000km. Tesla says the Model X, on sale from 2015, retains over 90% capacity over the same distance.
Again, there have been differences based on battery specs with reports indicating the 90kWh battery pack degraded a little more quickly than the 85kWh unit. Technological improvements have further aided durability and longevity, with the 100kWh having shown better performance.
Greater Longevity Guaranteed
Toyota has set a target with its new 2023 bZ4X insisting it will retain 90% of its battery capacity after 10 years or 240,000km.
The advancements in battery technology, especially with lithium-iron-phosphate (LFP) batteries, which are used by companies like BYD and CATL, and the anticipated advent of Solid-State batteries, are making a half-million-kilometre lifespan a realistic goal under optimal conditions.
Additionally, protective measures such as thermal management systems and charging restrictions have been implemented to further enhance battery longevity.
Tesla says the Model X retains over 90% capacity over 320,000km.
What Affects Battery Health?
Several factors contribute to the longevity of modern EV batteries such as Advanced Thermal Management Systems that maintain optimal operating temperatures, preventing overheating and reducing wear. Similarly, modern EV batteries are designed with built-in protection mechanisms that limit the maximum and minimum charge levels. These buffers ensure that the battery operates within an ideal range.
As an EV owner, you can actually take steps to care for your EV’s battery health and improve its lifespan. A crucial bit of advice is to NOT charge above 80%, and not let it drop below 20% charge. Charging to 100% increases stress on the battery, and completely discharging it can also reduce longevity.
Additionally, avoid using superfast chargers unless you’re really in a hurry as this too accelerates battery degradation. Avoid extreme temperatures and ideally park in shaded areas or garages. Excessive heat or cold can negatively impact battery health.
Most new EVs will have over-the-air software updates. Ensure this is enabled as manufacturers will often release new patches to improve battery health management. Finally, consider your driving style; gentle driving habits can reduce the strain on the battery and help maintain its capacity.
EVs are NOT like Smart Phones
The concerns about the short lifespan and high replacement costs of EV batteries have proven to be largely unfounded. Modern EV batteries are designed to last significantly longer than initially anticipated, with real-world data supporting their impressive durability. And rest assured as the EV market continues to grow, the durability and reliability of EV batteries will only improve further.
