Everyone has experienced a battery degrading on an electrical device at some point. Has your phone ever started taking ages to charge and then only lasting for a few hours before you need to charge it again? That’s the effect of your phone’s battery degrading.
The same thing can happen to electric cars, too. EV battery packs do degrade gradually over time. If you’re quite new to electric cars, this is something that could be a bit of a worry for you! If that is the case, we’ve attempted to answer some of the most common questions about battery degradation.
Why does the battery on an electric car lose charge or degrade?
The battery on an electric car can degrade due to multiple different things. These three things are temperature, cycles and time. Whilst the factors of battery degradation are a bit more complicated than just that, these are the three big factors that all group together to cause it.
In general, higher temperatures can seriously affect the lifespan of a car’s battery. Electric cars that are used in tropical or desert climates will have batteries that won’t last as long as those in colder or more temperate climates.
As a battery is charged up and then discharges over the course of being used, the process of doing that will cause the battery to degrade over time. This is especially the case if the battery is charged to full capacity every or almost every time.
Finally, batteries will just degrade on their own over time. This will happen even if you rarely or never use the battery. The batteries of electric vehicles are not immune to the passage of time and, eventually, it’ll catch up with them.
As electric cars have complex and advanced battery management systems and are stationary most of the time, you aren’t very likely to experience degradation through the batteries cycling through charging and discharging. Electric car batteries are more likely to degrade due to heat or simply being very old.
How much range do electric cars lose per year?
How much range an electric car loses per year varies quite a bit. Different cars with different battery packs all degrade differently. That can include the same model of car that has been made in different model years!
Thankfully, EVs don’t lose a lot of range per year. According to Recurrent, a platform that monitors more than 7,000 connected vehicles across the USA, it typically takes around 5 years for an electric car to have a 5-10% drop in range. This can be a fairly linear drop in some cars, whilst in others there can be a steeper drop within the first couple of years before leveling out into a much more gradual rate of degradation.
“Every electric vehicle loses range differently, including cars of the same brand or year,” Recurrent’s CEO Scott Case has said about the issue. “The good news, however, is that several early EV models show us that batteries last longer than people expect.”
Which electric cars have batteries that degrade the most and which have batteries that degrade the least?
This is a question that Select Car Leasing attempted to answer back in 2020. Using data gathered from a study by Geotab that analysed over 6,300 different electric cars, it came up with a list of the cars with the best and worst battery degradation.
The car that showed the least amount of battery degradation over a one-year period was the Chevrolet Bolt. The North American market-only series hybrid’s battery didn’t degrade at all and was the only model in the survey to have no degradation after a calendar year! 2019 model year variants of the Tesla Model 3 and Model X also showed relatively tiny amounts of battery degradation (0.6% and 0.7% respectively), as did the Nissan Leaf (0.8%) and the BMW i3 (0.9%).
Meanwhile, the Mitsubishi Outlander PHEV had the worst level of battery degradation within the first year of its life at a rate of 4.1%. In fact, the list of the worst offenders seemed to be dominated by PHEVs! The Kia Niro PHEV was the second-worst with 3.5% degradation, whilst the Toyota Prius Prime was third with 2.3%. The Volkswagen e-Golf was also in the top 10 of the poorest performers with a rate of 1.7% of degradation in the first year. All these things are perhaps worth bearing in mind if you were potentially looking at any of these cars…
Can you replace an electric car’s battery?
It’s definitely possible! If a car’s battery is worn out, you can have it replaced with a brand-new one. This is a very expensive job, though, unless it’s being covered by some kind of warranty. Most manufacturers will have some kind of powertrain warranty that will cover a battery replacement. As an example, Nissan’s one for the Leaf covers the battery for 8 years or 100,000 miles, whichever comes first. Tesla also has a similar warranty on the powertrains of its cars.
In some cases, a total replacement of the battery pack might not be needed. As the battery packs of electric vehicles are usually made up of multiple modules of cells, a single defective module can be replaced with a brand-new one. This avoids the huge cost of having to replace the entire battery pack and will also be covered under the powertrain warranty if the car is still within its terms.
Can I do anything to stop my battery from degrading?
There are some ways you can help to reduce battery degradation. One way that’s often recommended is to never fully charge the car’s battery. A lot of battery management systems in EVs can be set to only charge the car up to 90-95% capacity. This will help a lot with helping you manage how you charge your car, as the car will stop charging as soon as it hits a certain level of capacity.
When it comes to temperature-related degradation, if you live in a particularly warm climate where degradation will be higher there isn’t much you can do about that. There isn’t really anything you can do about time-related degradation, either. No matter how careful you are with taking active steps to afford battery degradation in other ways, age will eventually win out and cause the battery to degrade noticeably. This will take a long time to happen, though, if you’re careful in other ways.
Should I avoid buying a used electric car?
Absolutely not! Don’t let potential issues with battery degradation put you off buying a used EV. If you’re buying one that’s no more than 2-3 years old, it’s pretty likely that battery degradation won’t have affected it that much at all.
Is the thought of buying a used EV still a bit daunting and you’d like a bit of advice on it? Recurrent, which we’ve mentioned earlier, offers used EV reports for those based in the US who are thinking about buying a used EV.
