Good News for EVs: Your Battery May Outlive Your Car

We’ve had more than our share of negative news about electric vehicles of late, so I’m glad to share some significant positive information. One of the major concerns of potential EV purchasers is the longevity of the battery. In the same way the engine is the lifeblood of a conventional vehicle, the battery serves as the heart and soul (and biggest cost item) of an EV. A fleet management company with a deep expertise in telematics, Geotab, gathered data from 10,000 EVs and has been tracking them for more than five years. 

Charlotte Argue, Geotab Canada’s senior manager of sustainable mobility, drew a simple conclusion from reviewing the latest data — your battery has a good chance of outliving your car. Estimates based on the study are that the typical modern EV battery will last 15-20 years, while current data of the average car’s life pegs it at about 13 years.

The average degradation rate is 1.8% per year, significantly lower than some earlier estimates, including one from Geotab that saw batteries losing 2.3% per year. That’s all the more amazing since during the same period batteries have become cheaper, more powerful and, as this shows, more durable.

Argue also noted that battery degradation is not linear, i.e., not proceeding at a uniform rate. She said typically batteries initially (in the first year or so) drop. But then decline at a “moderate pace” until dropping off more in their latter years. Further, she noted that battery degradation is primarily noticed in reduction of an EV’s range, not in its power.

What affects battery life

A variety of factors impact battery life, according to Argue. We’re talking here about the lithium-ion batteries found in almost all battery electric and plug-in hybrid vehicles. She enumerated those factors:

Age: As batteries get older, they degrade, reducing capacity and vehicle range.

Temperature: Extreme heat or cold can accelerates battery degradation, which is why battery management is so important.

Operating State of Charge (SOC): If you keep your charge between 20% and 80% as much as possible, it will extend your battery’s life.

AC vs. DC Charging: Frequent DC fast charging may degrade a battery faster, compared to slower AC charging (your typical Level 2 home charger).

Usage: Each charge and discharge cycle moves the needle on aging of the battery slightly.

Battery chemistry: Different types of lithium-ion battery chemistries with names such as NMC and LFP, vary in durability, but may have other trade-offs.

Battery System & Thermal Management: Your car’s battery management system (BMS) is one of the most significant factors affecting the rate of decline in capacity. Systems that pre-condition batteries, for instance, can make charging more efficient and make the battery less stressed by the charging session.

Tips to extend your battery life

Watch the heat. High heat is not something batteries enjoy. A good BMS will help, but simple things like parking in the shade can go a long way.

Minimize DC fast charging if you can. Charging overnight with a Level 2 (240-volt) charger will extend your battery’s life. Keep the SOC between 20-80% if possible. Save full charges for long trips.

High vehicle use does not negatively affect battery life according to Geotab’s study (which focused on EV fleet use). Regular use of an EV actually encourages optimal health of the battery.

About the author

Michael Coates is an internationally recognized expert on automotive environmental issues. He publishes the Clean Fleet Report (https://cleanfleetreport.com/), writes for a variety of publications and also consults in the automotive industry.