There are a lot of myths and misinformation about electric vehicle (EV) batteries spreading around the web — and a lot of it stems from the uncertainty surround the coming electrification of the modern automobile. And with that comes a great deal of consumer trepidation and skepticism about the emerging technology.
So, we figured it might be time to do a quick Q&A with an industry expert to help sift through some common questions swirling around modern electric vehicles.
We tapped John Voelcker, an EV expert and automotive reporter for not only Car and Driver but also several other well-known publications. Here are his answers to some of the biggest questions surrounding EV batteries.
We don’t have enough real-world data yet to answer that with certainty because the majority of EVs sold since 2011 are still on the road. But all makers warrant their batteries against complete failure for 8 years/100,000 miles or 10 years/150,000 miles.
The more relevant question is probably how much capacity is lost over the vehicle’s lifetime. Though there’s no single standard, a car battery is usually considered “done” when it holds something like 75% of original capacity. Early data on Tesla Model S batteries was encouraging as indicated in this story.
Toyota says it will warranty the battery in its upcoming Toyota bZ4X electric crossover to retain 90% of its original capacity after 10 years. That’s laudable. I hope other makers follow suit.
So few people have paid to replace a pack outright that we really don’t know. Virtually all the packs that have been replaced so far have been under warranty.
And for older EVs (2011-2016) with ranges of 62 to 115 miles, replacing a low-range pack with a new one simply doesn’t make economic sense when newer EVs with 2 or 3 times the range are on the market.
Back in 2014, Nissan quoted a cost of $5,500 to replace a (low-range) Leaf pack.
But I’ve seen anecdotes of Tesla Service Centers quoted prices north of $20,000 for a new pack. While there are Teslas with more than 200,000 miles, the ones I know of with 400K or more have generally gone through one pack.
Again, though, consumers having to pay for total pack replacement is an extremely rare occurrence.
Repair, yes. Some packs that fail may just have light corrosion on connectors, or a single bad module.
Trained mechanic-electricians who are familiar with high-voltage equipment can carefully disassemble the packs, diagnose these faults and frequently repair them for a fraction of the cost of a brand-new pack (whatever that is).
But: Do NOT try these kinds of repairs at home!
Once an EV is out of warranty, most dealers will default to selling a new pack as the only solution—so repairs like these are done by third-party shops, just as they are today for hybrids.
All EVs have multiple checks and safety protections against “overcharging.” The car simply won’t let you put more juice into the battery than it can handle, and the car throttles charging accordingly.
Plugging it in to a Level 2 (240-volt) charging station above 50% may reassure some drivers; it doesn’t really affect battery life, because of the above.
There’s a lot of discussion about whether repeated DC fast-charging (at 24 to 270 kW, at a public charging network that uses a different connector) will harm battery life. So far I’ve not seen conclusive data that it does.
But very few people will charge exclusively using DC fast charging. Since four out of five households that can afford a new car already have dedicated off-street parking, they’ll do 80% or 90% miles on overnight garage charging.
That’s fine! Go for it if it makes you more comfortable! The car will protect itself.
Step one with all things is to educate yourself. Don’t believe half of what you see on social media or fall victim to the “I heard” or “I know someone who says” mentality. Electric vehicles aren’t mainstream yet, but that day is coming. Soon. And honestly, there’s a lot to like about EVs if you just look into them and give them a chance.
As always, we want to hear your thoughts. Do you have EV questions you want answered? Let us know, and we’ll work on a part two in a series on EVs.