A battery's charge, and maximum range can decline over time. For example, if a car that had an official range of 200 kilometres when it was new can now only charge to 80 per cent after a few years, then its actual maximum range is closer to 160 kilometres.Stellantis/The Associated Press
We’re considering getting an EV for our next vehicle and I’ve been doing a lot of research online. When any EV-related story has a comments section, invariably somebody mentions that EVs make no sense because the battery will need to be replaced after a few years. Is this true? – Mike, Kelowna, B.C.
In newer electric vehicles, it’s unlikely your battery will get a terminal diagnosis. In fact, it could potentially outlast your car, an EV expert said.
“Studies and plenty of anecdotal examples have shown that modern EV batteries will not degrade to the point that they need replacing,” said Michael Stanyer, the program co-ordinator with Plug In B.C., a Vancouver-based not-for-profit EV education program.
Like the battery in your smartphone, the lithium-ion battery in your EV can eventually lose its ability to reach a full charge.
Over time, its maximum charge could get lower and lower. The lower the maximum charge, the less range you’ll get.
For instance, if a car that had an official range of 200 kilometres when it was new can now only charge to 80 per cent after a few years, then its actual maximum range is closer to 160 kilometres.
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In these batteries, lithium ions move between two electrodes – the cathode and the anode – through a liquid electrolyte. They move to the anode when you charge it, and then back to the cathode as you use the battery. The chemicals in the battery break down the more times you run it to empty and then recharge to full.
But the biggest culprit when it comes to EV battery degradation is heat, Stanyer said.
When the battery gets too hot, that electrolyte starts to break down and the ions can’t move as easily back and forth.
“Heat is going to have the biggest impact,” he said. “And in our climate, that heat will mostly come from fast charging.”
Fast charging can replenish a battery to 80 per cent in about 30 minutes, depending on the car and speed of the charger. But it heats up batteries and can speed up degradation, Stanyer said.
Chilling out
To beat the heat, EVs now have battery-management systems that cool the battery – but some early EVs, such as the 2011 Nissan Leaf, didn’t, Stanyer said.
“Some of these 2011-era EVs can now be down to 50 or 60 per cent of their original charge, especially if they did lots of fast charging,” Stanyer said.
Stanton Zeff, a Texas owner of a 2011 Nissan Leaf writes that he has replaced his battery twice – once under warranty and then, last year, on his own, with a larger battery salvaged from a 2020 Leaf.
A battery is unlikely to degrade to the point where you can’t drive it; you just might not be getting the range you’d like, Stanyer said.
Batteries removed from EVs will “still have a very usable capacity,” for years, Stanyer said. They may find a second life powering equipment or storing energy on solar grids.
So how much should you expect a battery to degrade in a new EV?
Geotab, an Oakville-based transportation technology services company, looked at data from 6,300 EVs and found that, on average, they lost about 2.3 per cent of their starting range a year.
“But in most vehicles now, once it goes down to 90 per cent, it really levels off,” Stanyer said. “I came across a 2019 Hyundai Kona for sale that has 350,000 kilometres on the odometer and it still has a range of 365 kilometres – which is about 86 per cent of what it would normally have new.”
Typically, EVs have an eight-year, 160,000-kilometre warranty on batteries, Stanyer said. If your warranty is up, the cost of a battery pack can vary.
“I hear all sorts of things. I heard from a Chevrolet dealer that [a new battery] is about $10,000,” he said. “But I see people being quoted much more.”
But if you’re buying an EV now, future battery replacement is a “non-issue,” Stanyer said.
“I recognize that people are concerned about it,” he said. “But in terms of practical use of the vehicle, [it’s not a reason] to be deterred from buying an EV.”
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