Used EVs – Range Loss vs. Range Improvement

One of the biggest concerns people have about making the switch to an electric vehicle from an internal combustion engine is the life of the battery. The battery can often represent 30% of the cost of the vehicle, so battery failure would certainly be a devastating blow. The manufacturers of these vehicles, across the board, have taken this into account and offer warranties of 8 years and 100,000 miles on the battery, guaranteeing it works up to 70% of its original capacity. And the good news is that battery failure is exceedingly rare. A study this year by Recurrent Automotive showed that only 1.5% of all EV batteries have ever been replaced, going back as much as 10 years with the Nissan LEAF.

But for a used EV purchaser, where the battery warranty remaining is less than the original warranty and the remaining battery life may not be the same as when the vehicle was new, the questions remain: how healthy is the battery of this vehicle I am purchasing? How much range am I going to get if I buy a used electric vehicle versus buying a new one? The reality is that EVs are showing both range loss and range improvement, years after their original in-service date. At Green Wave Electric Vehicles, we have observed and studied these phenomena and can share our experiences and research.

First, let’s talk about range loss. Lithium-ion batteries exist in many of the products we use every day, from our tools to our computers and cell phones. We are all familiar with the battery depletion that we experience with these products. But while EV batteries are generally made from the same materials, they have sophisticated battery management systems (BMS) to prevent diminishing capacity. These systems include capacity buffers which make the usable capacity less than the total capacity. This prevents over-charging and over-depleting, which are detrimental to batteries. They also have conditioning systems that optimize battery temperature during charging and use. They also have computer systems that analyze the battery, the energy draw, the driving style, and climate control usage (heating the vehicle cabin takes a lot of electricity); these computers give a real-time battery health report to the driver in the form of its range meter.

Working together, these elements of the BMS have told a fairly consistent story: batteries don’t lose that much capacity in normal operation. Auto Week reported in 2022 that up to about 300,000 miles, EVs are going to lose about 1-3% of their range per year, with a more pronounced degradation in the first 2 years, and then “a slow decay of approximately 7% in 175,000 miles.” So, if you purchase an EV with 250 miles of original range, you can expect about 230 miles of range after 11 years. Not too bad!

But range improvement is possible as well! There are a couple of reasons that you might find a pre-owned EV to be showing greater range than the original EPA-rated range: (1) Recall-related battery replacement (like on the Chevy Bolt or Hyundai Kona EV), and (2) Improvements to the BMS through over-the-air (OTA) software updates.

First, the battery replacements. Chevrolet responded to a NHTSA safety recall on its Bolt EV batteries in late 2021, announcing that they would replace all batteries on 2017 and up model years related to fire risk. The original battery was a 60 kilowatt-hour battery, rated to deliver up to 238 miles of range. But the battery they replaced it with has a capacity of up to 66 kWh, and the range displayed on these vehicles can show 250 miles or more on a full charge.

Next, let’s look at the magic of OTA BMS improvements. In late 2021, Ford sent owners a letter indicating that they would deliver software updates that would give Mustang Mach E owners “improved range in cold weather.” At first, this update was only available via a trip to the dealership. But by the following year, owners were able to get these updates to their vehicles while they slept. I am a Mustang Mach E owner myself, and I woke up one morning to find my EV showing 286 miles on the range meter at full charge; the EPA range for my car is 270 miles when it was new. This phenomenon also occurred with the Volvo C40 and XC40 Recharge Pure Electric, which went from 208 to 223 miles in range, as reported by Motor Trend.

If you’re shopping for a used EV, the best thing to do is to check out the range on the gauge cluster when you turn it on. To figure out the total maximum range, you can divide the shown range by the state of charge percentage. So, if the range meter is showing 100 miles of range at 45%, you know the max range is about 222 miles (100/.45=222). Better yet, ask your dealer for a 3^rd party battery health report, like the ones provided by Recurrent Automotive. The bottom line is that you can buy a used EV with confidence and get great range – if you know what to look for and what questions to ask.