Currently reading: Battery life uncertainty prompts concern over used EVs

Battery analysis reveals rapid degradation in some models; some reaching "end of life" within eight years

Concerns are being raised about the usable lifespan of EVs, with specialist companies reporting some cars reaching ‘end of life’ battery capacity after just eight years – and some hitting that point even sooner. 

Silver Power Systems (SPS), a specialist in battery performance analysis whose software tracks and monitors battery data and health, says it has observed wide variations in performance, especially within fleets. 

“Across even a single fleet, variations in battery health can be up to 10%,” said Pete Bishop, founder and chief technology officer at SPS. “Considering that in most commercial applications, 80% battery capacity is deemed to be end of life in operational terms, 10% degradation represents half a vehicle’s life.” 

However, the definition of what constitutes ‘end of life’ depends on how the vehicle is being used, as Liam Mifsud, programme manager at SPS, explained: “Someone operating a specialist vehicle will probably keep it for longer and not regard 80% as end of life. If they don’t drive far, a private vehicle owner may also be happy with that capacity. However, we’ve noticed that when a battery gets to 70%, it degrades more rapidly.” 

SPS’s findings echo those of Geotab, a telematics provider. It also measures vehicle batteries’ state of health but goes further by publishing its findings in its Electric Vehicle Battery Degradation online tool. 

Charging

Its data is based on 6300 fleet and consumer EVs, represented across 24 makes and models. 

According to Geotab, average battery degradation over a six-and-a-half-year timeframe is 13.5%. Among those recorded by the tool are three model years of BMW i3, with the oldest, from 2017, recording a battery degradation figure of 16% after a little less than three years. 

Meanwhile, 2014 examples of the Nissan Leaf show 23% degradation after almost six years. After four and a half years, the batteries in 2015 Tesla Model S cars that Geotab sampled had degraded by 10%. 

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Autocar compared Geotab’s results with the same models being advertised by private sellers. A 2012-reg Nissan Leaf with 102,000 miles had, said its owner, only eight bars of the 12 showing on its range display, meaning its battery had degraded by around 30%. As a consequence, he said, the car had a real-world driving range of 50 miles. 

A 2015-reg BMW i3 with 33,000 miles had degraded by 19%. Its owner claimed that on a full charge and in Eco Pro mode, the car had a driving range in summer of 85 miles. A 2014-reg Tesla Model S with 70,000 miles displayed a range of 270 miles when fully charged, compared with 280 miles when it was new. 

Bmw i3 front three quarter tracking

In contrast to these private sellers, Autocar found that dealers were less forthcoming about their cars’ battery capacities and ranges. However, one specialist EV dealer has recently begun displaying the battery health of its cars in its advertising. Drive Green, based near Bristol, uses a plug-in battery monitor to generate a battery certificate that it displays with the car. For a 2014-reg Renault Zoe with 54,000 miles, the company quotes a battery state of health figure of 96%. A salesman said the garage is the only one in the UK offering the service. 

Some dealers are sceptical about the reliability of battery readings taken this way, however. One EV specialist told Autocar that it’s important to know what condition the battery was in before it was analysed by a third-party, plug-in system. “A warm battery will give a good figure, so sellers run the car first then check it,” he said. “I’ve seen it happen when dealers are selling to the public as well as to each other. This way, they get a better price for the vehicle. The best thing is to go by the car’s range display. We’ve sold hundreds of EVs, and on this basis, we see 1-2% battery degradation each year.” 

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One organisation that might be expected to have a clear picture of the scale of battery degradation is Recovas. The partnership – which includes EMR, a vehicle recycler; car makers including BMW; the University of Warwick; and the UK Battery Industrialisation Centre – is developing an end-of-life supply chain for the electric vehicle industry. As part of this work, EMR salvages end-of-life EV batteries. But EMR managing director Roger Morton said it’s early days as far as supply is concerned. 

Nissan leaf 2011 rear three quarter static

“EV batteries are lasting far longer than anyone expected,” he said. “Although batteries degrade over time, for third owners and beyond, driving range is less of an issue. The car is probably a second or third vehicle for short trips, and in any case the car is much cheaper than a new one, so they make allowances. 

“I see EVs easily lasting as long as ICE cars; possibly longer because they’re simpler. It’s going to be 2045, long after sales of ICE vehicles have ceased, before we start seeing end-of-life EVs with seriously depleted batteries in large numbers.”

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RightSaidFred 29 November 2022
My Peugeot Ion is 10 years old. Its 16 kWh battery (14 usable - when new) is degraded to approx 70%. In summer I can get 55 miles, in winter with the heater on full and often aircon to prevent misting, 30 max.

As an only car in HH, clearly it's useless. But in my multi car household it does all of the town trips, e.g. school run 4 miles each way twice a day. So despite being the cheapest and "worst car" (on paper) in the HH, it actually covers the most miles per year because its fitness for purpose for most of my journeys is perfect. 16-25 miles a day, rarely over 40mph.

I will have a decision to make on what to do with it when the battery degrades further. I could lease something like a VW e-Up which would cost £6k over 2 years with nothing to show for it at the end. Or I could buy a new battery pack for similar money and massively extend the life of the Ion (doubling its original range too!). Everything works, it's fun to drive, the Up et al seem very boring and conventional in comparison.

The Colonel 29 November 2022

A very click bait headline with a very click bait first paragraph that is simply not borne out by the rest of the article which, from several of the comments here, simply hasn't been read.  Headline and first paragraph doing its job then, it seems.

Jesus Chrsit!  Even someone that is among others trying to build a supply chain in the recylcing and reuse of old EVs, states that EV batteries are lasting longer than anyone expected, and things will improve.

That's the problem with this debate and the ICE fetishists that simply can't let go.  People approach it as if everything stays the same, which explains the wilful misinterpresting of what Bol wrote...because to acknowledge that 10 year old tech still has some life in it, relative to what it started with, even after 6 figure mileage, is to acknowledge, in fact, how far things move on over time.

Unless, of course, every 6 litre engine, now, outputs the same as a 6 litre engine from 100 years ago...with the same fuel consumption.

 

CarNut170 29 November 2022

Don't touch a second hand BEV with a bargepole - noted.

xxxx 29 November 2022

And yet Telsa model 3, amongst other BEV's, residual value are superb. Noted.