Study Shows EV Batteries Maintain Nearly 90% Capacity After 200,000 km

A recent study has shed some light on the longevity of electric vehicle (EV) batteries, suggesting that they may be more durable than we previously thought.

The research, carried out by P3 in partnership with Aviloo, analyzed real-life data from over 7,000 EVs to understand how batteries degrade over time.

The findings are quite promising for EV owners. Initially, batteries do experience a faster decline, dropping to about 95% of their original capacity after the first 30,000 km.

But it’s not all downhill from there. Interestingly, the decline in battery health slows significantly after this point.

By the time an EV hits 100,000 km, the average battery maintains around 90% capacity, and this figure remains fairly stable, even up to 300,000 km, where capacity hovers around 87%.

This performance exceeds the expectations set by some original equipment manufacturers (OEMs), who offer warranties predicting battery health could drop to 70-80% after a set period or mileage.

Most standard EV battery warranties cover eight years or 160,000 km, with some extending up to 10 years or 250,000 km.

So, what’s behind this initial drop and the subsequent stabilization? The study points to the formation of a solid electrolyte interphase layer on the battery’s anode during the first few charge cycles.

The variation in this process, influenced by the battery’s chemical setup, plays a big part in the initial capacity loss.

Another key takeaway from the study is the impact of driving and charging habits on battery health.

High currents, often resulting from rapid charging, quick acceleration, or high-speed driving, can negatively affect the battery’s state of health.

Conversely, moderate driving speeds and careful charging can significantly extend a battery’s life.

For EV drivers and fleet managers, the message is clear: gentle driving and charging practices are not just good for safety and efficiency; they also prolong the life of your vehicle’s battery.

This longevity could mean that, beyond their life in a car, these batteries could have a second career in stationary energy storage, potentially extending their usefulness to 20 years or more before recycling is necessary.

P3’s study moves away from theoretical data and provides a real-world look at how EV batteries can stand the test of time, especially when handled with care.