We know that electric cars don’t have engines with thousands of parts, complicated gearboxes, clutches or exhaust and catalyst systems, so what is there to break?
At a very basic level an electric car consists of a huge battery, electronics to regulate how much power it puts out and how it’s charged, and electric motors (sometimes called traction motors) to turn the wheels.
All the power can be developed and sent to the wheels straight away, without the need to build up through gears like a petrol or diesel car. Most electric cars have only a single-speed gearbox – a bit like a fixed-gear bicycle. If you push harder on the accelerator, the electric motor just spins faster. If you want to reverse, it spins backwards.
An EV’s braking system is backed up by the ability of the motor to slow the car down and push and electric charge back into the battery, which is called regenerative braking.
Few models of electric car have been on the market for very long, so any data on what goes wrong with older ones is from owner surveys and claims for repairs under warranties.
In the 2021 What Car? reliability survey of electric cars up to five years old, based on the experiences of more than 16,000 owners overall, the happiest in the electric category had the last-generation Nissan Leaf (2011 to 2018) with a 99% rating. Least reliable was the Jaguar I-Pace (from 2018) with lengthy stays in service departments trying to fault fix.
MotorEasy, which is one of The Car Expert’s commercial partners, provides reliability data for our industry-leading Expert Rating Index from its extensive database of car warranty claims. It also offers a specific EV/hybrid warranty separate from its internal combustion-engine (ICE) warranties.
The most detail it has on older EV faults is from cars that have been on sale the longest and sold in the greatest numbers. It has some interesting data on the Tesla Model S and Model 3 (dating back to 2014 and 2019, respectively), the BMW i3 (as far back as 2013) and the Renault Zoe, which has also been in production since 2012 with many updates.
As there were fewer EVs around over the last ten years from which to draw data, it can’t be said conclusively that electric cars are more or less reliable than similar petrol or diesel cars. Many people say they are more reliable, but most EVs have not yet had time to rack up the 100-150,000 miles we see over a typical car’s life cycle.
“I’m not sure we ever draw conclusions,” says MotorEasy chief operating officer, Matthew Tumbridge. “We just report on what we find. What we find is we’ve seen some very big claims on Renault Zoes, traction motors on BMWs seem to be the weak spot in their system. On Teslas we see a lot of medium-sized problems; modules, pumps £500-£600 for this or that.
“The smaller the vehicle, the more tightly packaged and therefore the more brutal the repair cost, which is why the Renault Zoe is so very expensive to repair.”
What does go wrong?
The good news is that it’s not the battery (the biggest component by cost) that generally gives trouble. Those are where the engineering effort has been concentrated, and across the board they have longer, separate, warranties to the cars, typically eight years or 100,000-miles.
The problems are usually found with the components which are connected to the battery. From its claims data, MotorEasy has found that faults on electic cars more than three years old divide into these four categories:
Software: Complex software controlling electric cars can lead to longer diagnosis times if faults occur. Even main dealer workshops can be unsure of what they’re dealing with.
Gadgets: Failed touchscreens, cameras and pop-out door handles are expensive replacements, with few or no repair options. Obviously, these are certainly not exclusive to electric cars and can equally fail on petrol or diesel models.
Electric drive system: While batteries and electric motors tend to be robust, components such as sensors and controllers can be less reliable.
Suspension/wheels/tyres: As with combustion cars, these are easily damaged by potholes and traffic calming features. The greater weight of an EV doesn’t help for tyre or suspension wear.
The MotorEasy data is strewn with small costs for small parts and not all of them electric; door handles on Teslas seem to be a weak spot at around £350 to £500 for each repair. Taken in isolation, the cost of other spare parts for EVs can be eye-watering.
A battery control unit for a BMW i3 claimed at 17,200 miles was £6,540. A single traction motor (they have one to three) for a Tesla Model S was £2,211 at 70,672 miles.
However, it’s also important to remember that when some conventional cars go wrong, the bills can be just as crippling. A new engine for a Range Rover can cost £15,000 and a new Audi gearbox £7,000.
Since the path to EVs was accelerated by the UK government’s announcement of a ban on sales of combustion-engined cars from 2030, public interest has grown at a rate carmakers struggle to keep up with. “The change in law was the big thing, says Tumbridge. “As soon as the government announced that you had to stop selling combustion engines suddenly the public’s view on EVs changed, so the cars were pushed out of the door quicker by the factories and it’s not a huge surprise that some of the components seem to be flimsy.”
The electric fixing problem
Because fossil-fuel cars have been around for decades, main dealers and thousands of independent garages can diagnose exactly what is wrong in minutes with your petrol or diesel. However, even those dealers are just getting to grips with learning how to find and fix EV faults and there are very few independent garages or specialists which are able to deal with older electric cars.
This will change with time. For a start the Hybrid and Electric Vehicle Repair Alliance is a UK association of ‘EV-friendly’ independent garages where members are vetted for the right qualifications, tools and equipment to service and repair electric and hybrid vehicles.
The faulty EV issue is not so much greater unreliability, but an inability to diagnose problems when they occur. “There’s nowhere near enough EV understanding or technicians, the equipment and processes are all new and that’s just at the top end dealer level,” says Tumbridge.
“For the private motorist, it’s the worst possible situation because when you go into a £200-an-hour main dealer they may know quickly what problem is you get a fixed price and that’s fine. The problem is when they don’t know and they spend several hours with the vehicle. You’ve got this open-ended bill clocking up.” For any car he advises giving a dealer one hour before challenging them about going any further.
The Renault Zoe does have a particular problem, according to Tumbridge. “It’s a very compact, ambitious EV. There are hundreds on the road not causing a problem, but as soon as they do have a problem it’s very many hours to get to anything. One of our customers had a standard air-conditioning problem. To get at it involved the whole body coming off. It was too much money so the dealer bought the car back off him.”
So, should people be put off buying older EVs right now? “I think it should put people off owning old EVs, not new EVs,” says Tumbridge. Or, if you are buying a used EV, make sure you get a decent extended warranty that covers the main drive battery.”
This article was originally published in May 2022. Last updated July 2023.