EVs have been around for 15 years and with over 1.5 million on UK roads, we now have enough data to understand and predict the lifespan of the HV battery (that’s the High Voltage battery that fuels the car). The average lifespan of a petrol/diesel (or ICE) car in the UK is 17 years/123k miles whereas the predicted average for an electric car is coming out ahead at 18.4 years, or 124k miles according to a study by London School of Economics and University of Birmingham.

This is great news and not a surprise to EV Experts – we have been testing battery health in electric cars for many years. We expect that lifespan to increase further because we are already seeing EVs with great battery health and more than 175k miles on the clock. The British Isles are an HV battery’s happy place because temperatures are mild without long periods of extreme heat or freeze. As a general rule we are seeing a drop (or degradation) of up to 2% a year.

But what does the drop mean?  If a 5 year old car has lost 10% of its capacity, its battery health is 90% and this means it will achieve 90% of the range it offered when new. So, if you bought a brand new EV with a range of 257 miles, after 10% degradation it will achieve around 231 miles on a full charge.  At the predicted end of its useful life (18.4 years) it will be managing around 162 miles of range unless degradation has been at a higher rate than “usual”.

OK, so what are the main things that cause an HV battery to degrade?

1. Age – batteries degrade over time and generally age is more relevant than mileage. Before buying, ask for a battery health test to check where the battery is at. If it has degraded by more than 2% per year you can expect the car to be lower priced as its range will be a little less than an equivalent model with better battery health.
2. Heat – batteries that have been regularly rapid charged at speeds of 100kW or more are experiencing faster degradation. This is because the faster the charge, the more heat builds up in the battery and over time this can prematurely age it.  Using slower charging at under 50kW from kerbside chargepoints or car parks offering overnight charging or at home, is not only cheaper but will also prolong your battery’s life.
3. Habits – keeping the charge between 20% and 80% usually improves battery health over the long term. If your car sits unused for several weeks or more, it is important to leave it between these two levels. You can set the maximum charge level on most cars. If you only drive a few miles a day, charge your car once or twice a week rather than daily very small top-ups.

More reasons not to worry:

• Most electric cars come with an 8 year HV battery warranty from date of registration. Extensions or third-party warranties are available once your car is more than 8 years old.
• HV batteries are modular. This means that individual modules can be replaced – you don’t have to buy a whole new battery if some of the cells fail.  A typical module costs around £1,500.
• Fully electric cars are 82 times LESS likely to catch fire than ICE cars because they have no flammable liquids or sources of ignition. HV batteries are safely protected in steel cages – an EV fire is a very rare thing.

At EV Experts we include in every car’s factsheet its battery health, the adjusted realworld range and the original WLTP (manufacturer) range estimates so you can buy with confidence. Come and talk to us today about your next electric car.

If you would like to read more about HV batteries in electric cars, check out the AutoCar article here: https://www.autocar.co.uk/car-news/advice-electric-cars/how-long-do-batteries-last-electric-cars