A guide to electric battery life

Battery life is one of the biggest worries potential buyers have when considering an electric car. Along with range – and the fear of running out of power mid-journey, known as range anxiety – the way an electric car’s battery might degrade over time is a big concern.

Like any battery, the batteries in electric cars will lose some of their capacity over time. So, how long do car batteries last and how can we extend the electric car battery life?


What are EV batteries made from?

Most electric car batteries are made from lithium-ion, and work in the same way as batteries in household appliances, mobile phones and laptops.

This means their power capacity will decline over time, resulting in approximately 80% of the original capacity after eight years of daily use.

How long do electric car batteries last?

Electric car batteries undergo cycles of 'discharge' that occur when driving and 'charge' when the car is plugged in. Repeating this process over time affects the amount of charge the battery can hold, which decreases the range and time needed between each journey to charge.

The current prediction is that an electric car battery life will last from 10-20 years before it needs to be replaced. Advancements in technology, however, mean that the latest electric car batteries have a longer lifespan than ever before, including the MG ZS EV which comes with a 7 year/150,000 km warranty.

This might seem remarkable when the battery in your mobile phone begins to wear out after only a couple of years, but during that time it might be fully charged and discharged hundreds of times. Each of these so-called charge cycles counts against the life of the battery. So, after perhaps 500 full cycles, a lithium-ion phone battery begins to lose a significant part of the capacity it had when new.

While a couple of years might be acceptable with a phone, it's not good enough for a car designed to last many thousands of miles, so electric car manufacturers go to great lengths to make the batteries last longer.

In an electric vehicle like the MG ZS EV, batteries are 'buffered', meaning that drivers can't use the full amount of power they store, reducing the number of cycles the battery goes through. Together with other techniques like water-cooling systems, this means that electric car batteries should last for many years.

How to prolong electric car battery life

The lifespan of the battery pack often depends on how much it’s charged. You can extend the life of the batteries by only charging them between 20% and 80% and trying not to let them drop below 50% too often. Going beyond these limits can increase the rate that the battery deteriorates over time. Overcharging can also cause chemical changes inside the battery itself, which again could negatively affect how efficiently it can store energy. Ultimately, you’re looking to reduce the number of charging cycles your battery goes through in its lifetime.

Another factor is temperature. Extreme cold or heat can negatively affect your car’s battery and therefore the range you can travel, so it’s worth bearing this in mind.


Why does an electric car battery lose charge?

Over time, the cycles of ‘charge’ and ‘discharge’ every lithium-ion battery undergoes can reduce how much charge the battery can hold, and therefore how far your electric car can travel before needing to be recharged.

Replacing an electric car battery

The electric car battery life is around 10 years on average, with some lasting up to 20 years. So there’s no need to be concerned about replacing the battery before you’ve even bought a new car.

Leaving your battery flat and your car out of use could result in the battery pack no longer accepting charge, which is called bricking. But a lot of EVs, including the MG ZS EV, have systems that prevent the battery fully depleting.

You may find the battery loses its capacity over time. This is natural, and often due to extended use. In the event of a battery fault, consult your warranty first.