Electric and hybrid car warranties

Worried spent batteries in used electric cars will ruin your bank balance? Fear not, thanks to used electric car and hybrid warranties

James Wilson
Oct 26, 2021

Electric and hybrid models are sophisticated machines, full of the latest battery and electric motor technology. The thought of anything going wrong is enough to bring owners out in a sweat. To reassure buyers, manufacturers are offering generous warranties to cover the most expensive components for a number of years. But what happens when these guarantees do expire?

Well, largely the same as for petrol and diesel models; you can either continue driving without any cover or take out a used car warranty. There's a number of comprehensive warranties on the market specifically designed to shield those buying a used electric car from large repair bills.

Strangely enough, when comparing a battery-powered car to a diesel or petrol alternative, there is significantly less to go wrong. Internal combustion engines (i.e. those powered by petrol and diesel) have all manner of bearings, seals, springs, valves and pistons that require regular maintenance and/or checks to be kept in tip-top condition to ensure they continue to run smoothly.

The ‘engine’ of an electric car is an electric motor - which is made up of a handful of fairly straightforward components - such as copper wire and magnets. Likewise, an electric car's fuel system is its battery and even though the chemicals inside are rather fancy, there are very few moving parts.

That said, if one of the major parts of an electric car completely fails it's likely to be an expensive fix, which means a warranty could well be worth its weight in gold. Not all warranties are born equal, though, so it is important to understand which components are covered. With that in mind, below is an overview of the major components that make up an electric car and are the ones you'll want to make sure are covered by any electric car warranty.

Electric/hybrid cars: major electronic components

When thinking about electric cars, the headline components are; the battery pack, drive motor(s), high-voltage inverter, energy/power control module, reduction gearbox, regenerative braking system and charging unit. A self-charging hybrid or plug-in hybrid model also features an internal combustion engine, along with a more conventional automatic gearbox to send power to the wheels.

We're not expecting you to know how an electric or hybrid car works, so the explanations below will shed some light on each of these components, so you can get a feel for what they do and why they're vital for the car to be able to operate.

Battery pack

This is the set of batteries that powers the electric motor (or motors) which turn the wheels. The size of a battery pack is described in kWh (e.g. 50kWh in the Vauxhall Corsa-e), and is often discussed because a larger capacity means an electric car will be able to go further between charges, just like having a bigger fuel tank. Even electric cars are normally still fitted with a smaller low-voltage battery as well, that's used to power safety or start-up systems, but this shouldn't be confused with the battery pack.

Drive motors

The electric motor(s) takes power from the batteries and uses it to accelerate the car. Most affordable electric cars like the Nissan Leaf and Volkswagen ID.3 feature one electric motor powering either the front or rear wheels.

Powerful electric SUVs and performance models like the Tesla Model X typically have two, or sometimes even three, electric motors, powering all four wheels for extra performance and go-anywhere ability.

Hybrid and plug-in hybrid cars have a petrol or diesel engine and one or more electric motors, and in normal driving the car's onboard computer decides how to juggle between them. Most, like the Toyota Prius, also offer an EV driving mode, to keep the car in its electric mode when there's enough charge in the batteries. This is especially useful when driving in a city centre to avoid tailpipe pollution.

High-voltage inverter

Battery packs can only supply direct current (DC) electricity but the types of drive motors used in electric cars require alternating current (AC) to work.

We won’t get bogged down in the technical details, but inverters are used to convert electricity from DC to AC. It is fair to say that a faulty inverter will soon halt any progress down the road.

Energy/power control module

Even though EVs still have an accelerator pedal, you need something which turns how far you press the pedal into how much electricity is sent from the drive battery to the drive motor. This is what the energy/power control module does. It is also useful for sending different amounts of electricity to different drive motors (if a vehicle has multiple motors).

It is possible to combine inverters and control modules into one mysterious box - after all, it makes sense for the part of the car which tells the battery how much electricity is needed to be connected to the part of the car which converts the battery’s DC supply to AC. As a note, the energy/power control module (EPCM) can sometimes be referred to as a power delivery module (or PDM for short).

Reduction gearbox

Unlike petrol and diesel cars, electric cars do not have a conventional gearbox. That said, many have a 'reduction gearbox', which does exactly what it says on the tin and reduces the speed at which a car’s wheels turn in relation to the motor.

If that is hard to follow, imagine being on a bike in a gear where your legs are pedalling around furiously but the back wheel is turning slowly - the electric motor spins far faster than the car's wheels.

Regenerative braking system

The regenerative braking system in electric and hybrid cars puts charge back into the batteries when decelerating. To do this it uses all the same components that are used to take charge from the battery but in reverse order, with the electric motor becoming a generator.

Pumping electrons back into the battery pack creates resistance which can also slow a car down, and feels a bit like taking your foot off the throttle in a petrol car in a low gear. Some models allow the driver to increase this braking effect, putting more energy into the batteries and also meaning the brake pedal can be used less often. Several EVs like the BMW i3 and Fiat 500 feature a 'one-pedal' driving mode, which can bring the car to a halt using this effect alone, making urban driving simpler once the driver gets used to it.

Charging unit

The function of a charging unit is one of the easier things to understand about an electric car - they simply work by managing the electricity coming from a socket or public charger so that it can be used to charge the onboard battery. They can get awfully complicated, but in essence, all you need to know is the charging speed measured in kW. For example, a car that's able to charge at 100kW can be topped up twice as quickly as a model with 50kW charging. Our handy guide to charging an electric car explains this in more detail.

BuyaCar electric and hybrid car warranty

All electric cars purchased through BuyaCar.co.uk come with a minimum of 30 days warranty but there is the option to extend this. The annual or monthly costs (depending on how you choose to pay) vary from one car to the next and BuyaCar has partnered with Warrantywise for used car policies.

Warranty cover can be sourced for vehicles that are up to 12 years old and with up to 120,000 miles on the clock - which is well beyond the age or mileage any car maker offers and covers all the cars available on BuyaCar. These extended warranties cover all the major electrical components listed above.

Do hybrid warranties differ from electric car ones?

No, there aren’t any major differences between how used car warranties work for hybrids and fully electric vehicles. What is slightly different, though, is that hybrid warranties cover a wider range of components - as hybrids include additional mechanical parts, such as a petrol or diesel engine, and this results in slight variations in price.


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