EV batteries should last 20 years or more – and that’s better than petrol engines, new report claims

One of the biggest concerns when switching to electric cars is the lifespan of the batteries, with some drivers even fearing that they will have to replace them at high costs.

But a new report attempts to allay these fears by claiming that batteries in new electric cars could last 20 years or more.

Research conducted on 5,000 real modern electric cars shows that batteries show signs of degradation more slowly than components used in cars with a combustion engine.

The bold claims are made by Geotab – a leading company in fleet and corporate telematics, which tracks and connects vehicles to the internet.

The company says it has analyzed the battery health of nearly 5,000 electric fleets and private vehicles, using 1.5 million days of telematics data to examine how the latest battery technology can withstand the rigors of everyday use.

The data shows that electric car batteries in current models degrade by an average of 1.8 percent per year.

When the company conducted the same study in 2019, it found that battery efficiency was declining by an average of 2.3 percent per year, suggesting that progress has been made over the past five years to extend the lifespan of the technology.

The report further states that electric car batteries ‘generally degrade more slowly than combustion engine drivetrain components’.

David Savage, Vice President for UK and Ireland at Geotab, adds: ‘These higher levels of sustainable health mean that the batteries in the latest EV models will last well beyond the usable life of the vehicle and are unlikely to need replacing.

‘Yet we see that battery reliability is still used as a stick behind the door to beat electric vehicles.

“Hopefully, data like ours can finally debunk these myths.”

The report found that an average 1.8 percent decline in battery health is unlikely to have a significant impact on most drivers’ daily needs.

It is stated that this degradation will decrease in the future due to the arrival of new EV models and further developments in batteries, such as solid-state battery technology.

“People need to be confident that many of today’s electric vehicles are suitable and cost-effective to replace a range of light, medium and heavy-duty ICE vehicles,” David continued.

How the EV battery analysis was performed

Geotab calculates degradation using telematics data collected during charging.

This divides the kWh added during a charging session (or removed while driving) by the change in state of charge increase for each qualifying charging (or trip) event.

This calculation is performed based on recent charges (and journeys) and gives an estimate of the current battery capacity. If you divide this by the vehicle’s starting battery capacity (battery capacity for that make/model when new), you will get a ratio.

The weekly or monthly average for each vehicle is then used to create a data point over time.

Geotab then uses curve fitting based on make-model-year for all weekly average points for each vehicle model.

The data is based on 21 different EV models, the best performing of which show an annual battery degradation of just 1 percent.

Possible factors that cause batteries in some vehicle models to deteriorate faster on average than others include the chemistry of the battery and the thermal management of the battery pack.

“While current electric vehicles primarily use lithium-ion batteries, there are many different variations in lithium-ion chemistry and this affects how the vehicle responds to stress,” the Geotab report said.

‘In addition to cell chemistry, temperature control techniques also differ per vehicle model.’

Another important distinction is whether the battery is cooled and/or heated by air or liquid.

A surprising finding from the study is that electric cars with high fuel consumption did not show significantly faster battery degradation than other cars.

“This should be particularly good news for fleet operators, as electric cars offer better value for money the more they are driven,” the report said.

What is battery degradation and should it stop you from making the switch to an electric car?

Battery degradation is a natural process that permanently reduces the amount of energy a battery can store or the amount of power it can deliver.

The batteries in electric vehicles can typically deliver more power than the drivetrain components can handle.

As a result, electric vehicles rarely experience a decrease in power. Only the loss of the battery’s ability to store energy is significant.

The condition of an EV battery is called the State of Health (SOH).

Batteries start their life at 100 percent SOH, but over time they degrade.

For example, a 60kWh battery with 90 percent SOH would effectively deliver the same performance as a 54kWh battery.