Big announcements have been made this week about electric cars and the batteries that power them.
Tesla’s Battery Day saw ceo Elon Musk promise ‘tabless’ battery in the next three years that will be up to six times more powerful than those currently used in the US firm’s vehicles, while VW said it guarantees that the lithium-ion pack in its new ID.4 SUV will have 70 per cent capacity after 100,000 miles or eight years.
It begs the question: how long do batteries in plug-in vehicles last? A Canadian firm collects data on battery degradation on electrified cars and says that on average they shed two per cent of their performance after 12 months – we’ve listed the UK-available models in order of how rapidly capacity declines.
Electrified car battery degradation revealed: Analysis of battery performance in electric and hybrid vehicles has outline how much capacity they lose after the first year
With the ban on petrol, diesel ans hybrid cars potentially being fast-tracked by a decade to 2030, demand for electric vehicles is unquestionably going to spike.
Various studies have analysed consumer appetite for EVs, with the latest being a What Car? poll of 12,029 in-market car buyers.
It found that three in five (59 per cent) are now considering an electric or a hybrid vehicle as their next motor.
How Geotab calculates battery degradation…
Geotab’s methodology for the electric vehicle battery degradation tool is a follows:
Geotab calculates battery degradation by taking the kWh added during charging and dividing that value by the change in the State of Charge increase for every qualified charge event.
This calculation is taken over recent charges, provides an estimate of the current battery capacity, which when divided by the vehicle’s starting battery capacity (battery capacity for that Make/model as new), obtains a ratio.
Geotab then takes the weekly or monthly mean for each vehicle to create a data point over time.
After, Geotab uses curve fitting by make-model-year for all weekly mean points for each vehicle model.
Some 6,300 vehicles were included in this analysis representing 64 make and model years.
The results come after the UK automotive trade body revealed that electric and plug-in hybrid vehicle registrations had risen by 157 per cent and 68 per cent year-on-year, respectively in the first eight months of 2020.
But one of the big questions on the minds of drivers is how long the batteries will last – and how quickly they will lose performance.
A report published in December by Plug In America – and analysed by NimbleFins – reviewed the condition of a typical Tesla Model S battery.
It claimed that after seven years of use – and repeat charges – the batteries will have 93 per cent of its original capacity remaining after seven years, suggesting it loses just one per cent a year.
However, Canadian company Geotab says that, on average, drivers should expect electric vehicle batteries to degrade almost twice as rapidly.
Its EV Battery Degradation Tool assesses the average depletion in capacity of electric vehicle batteries over time by measuring the performance of 6,300 fleet and consumer plug-in cars.
Select Car Leasing has reviewed its database of information, identifying which models are sold in the UK and ordered the cars by how quickly capacity disappears in the first 12 months of use.
Electric and plug-in hybrid cars ranked by calculated battery degradation after 1 year
1. Audi A3 Sportback e-Tron (2017) 0.3%
2. Tesla Model 3 (2019) – 0.6%
3. Tesla Model X (2019) – 0.7%
4. Nissan Leaf (2019) – 0.8%
5. BMW i3 (2019) – 0.9%
6. Ford Focus EV (2017) – 1.1%
7. Tesla Model S (2019) – 1.1%
8. Mercedes-Benz B-Class Electric Drive (2018) – 1.2%
9. Volkswagen Golf GTE (2017) – 1.4%
10. Kia Soul EV (2018) – 1.6%
11. Volkswagen e-Golf (2019) – 1.7%
12. Toyota Prius Plug-In (2019) – 2.3%
13. Kia Niro PHEV (2019) – 3.5%
14. Mitsubishi Outlander PHEV (2019) – 4.1%
Source: Select Car Leasing using Geotab data
The electrified models that lose the most battery capacity in year one
Geotab’s analysis aims to understand how real-world conditions influence the battery health of electric vehicles, providing aggregated average degradation data for 21 vehicle models available across global markets.
It says its data offers ‘insight into average battery health over time’, but it ‘should not be interpreted as a precise prediction for any specific vehicle’.
Comparing the findings on its tool, Select Car Leasing said the Mitsubishi Outlander PHEV was most likely to shed capacity, with the calculation suggesting it loses around four per cent in the first year.
The Kia Niro Plug-in Hybrid was next on the list, with calculated battery degradation of 3.5 per cent on average, ahead of the Toyota Prius ‘Prime’, with the Prime distinction in the US being the Prius Plug-in Hybrid in the UK.
At the opposite end of the spectrum, the analysis shows that Teslas lose around one per cent capacity – in line with previous data from Plug In America.
According to the database, the Mitsubishi Outlander PHEV is calculated to shed over 4% battery capacity in the first year, making this the worst performer of all the vehicles analysed
The Audi e-tron Sportback, which is no longer on sale in the UK, was calculated to have the slowest battery degradation of all electrified cars reviewed
The no-longer-available Audi A3 e-tron topped the charts with just 0.3 per cent degradation, while it’s sister brand Volkswagen also performed adequately with the previous generation Golf GTE plug-in hybrid and the now defunct e-Golf – which has since been replaced with the all-new ID.3 hatchback.
While these figures suggest battery degradation will ultimately be part of EV ownership, advances in technology should see capacities retained at a higher rate.
And all electric and hybrid car makers provide separate warranties for the batteries in their vehicles.
For instance, Nissan’s Leaf comes with eight-year 100,000 cover for the batteries while the Hyundai Kona Electric warranty is for eight years or 125,000 miles of usage.
As for Tesla, customers received a new-vehicle warranty for a period of eight years or 120,000 miles, whichever comes first, with minimum 70 per cent retention of battery capacity over this period.
If batteries are found to have dropped below a certain performance level, the manufacturer is responsible to replace it with a new one at no cost.
Tesla cars – like the Model 3 pictured – lose around 1% battery capacity in the first year, according to Geotab. That level of degradation is consistent with other reports
Nissan’s Leaf comes with eight-year 100,000 cover for the batteries
Emergency EV roadside charging services are becoming the norm
LV= General Insurance is this week rolling out a new, market leading service offering roadside charging for electric vehicles that run out of charge.
The pilot, which has been launched in partnership with AFF, the national roadside electric vehicle charging assistance company, will see 10 AFF recharge vans provide mobile charging facilities on roads across England and Wales, including the hard shoulder and emergency refuge areas of motorways.
Explaining the reason for the new service, Tom Clarke from LV said: ‘As people still run out of fuel in their petrol cars the same will happen with EV’s but to support the electrification shift we want to provide this additional support.
‘Our own research shows range anxiety as the third biggest reason why customers are put off owning an EV with 17 per cent stating this puts them off buying one. By us improving our current offering further we hope to ease those concerns so for the few people who do claim they have the comfort of knowing they won’t be left in the lurch.’
Around 80 RAC patrol vehicles across the country are now fitted with an EV Boost unit to provide 10% charge to electric cars that have ran out of juice
Do motorists really run out of juice in their EVs?
The UK’s biggest breakdown provider, AA, says less than 4 per cent of EV breakdowns it attends are for motorists running out of battery charge – a figure that’s dropping year on year.
The majority of breakdowns involving plug-in cars is due to punctures, which is the most common cause of call-outs for all fuel types.
EV breakdowns are around 2 per cent of the AA’s overall workload but understandably this is increasing as the EV parc increases, it said.
The RAC reports a similarly low volume of EVs running out of charge on the road.
However, a spokesman for the provider said 80 of its patrol vans across the country are now fitted with an EV Boost unit.
This is a the first lightweight, mobile electric vehicle charger system capable of giving stranded out-of-charge vehicles an up to 10-mile power boost from a generator in the breakdown van.
‘Most EVs can’t be towed normally and need to be transported with all wheels off the ground which usually requires a flatbed vehicle,’ the RAC explains.
‘So if an electric vehicle runs out of charge in a busy urban locations like red routes in London or even just a narrow road, it can be very problematic.
‘This enables our patrols to help stranded EV drivers at the roadside with a power boost, equivalent to a top-up from a fuel can for a petrol or diesel vehicle, to get them on their way again.’
Want to know which EVs currently on sale in the UK have the longest (claimed) driving ranges? Read our full top 10 report here.
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