How many years does an EV battery last?

The average loss is around 2% a year, leaving about 80% of capacity after 8 years. At that rate the battery is expected to stay usable for 15–20 years. Most manufacturers give an 8-year or 160,000 km warranty.

At what SOH does the battery need replacing?

There is no fixed limit; a battery at 70–80% SOH keeps working, just with less range. The warranty usually covers a drop below 70% within 8 years.

Does DC fast charging damage the battery?

Occasional DC charging is normal use, and the car protects the battery according to its temperature. Doing all your charging on high-power DC all the time can speed up the loss somewhat; charging at home day to day is best.

How do I check the battery on a used electric car?

Ask an authorised service centre for a written SOH report, and ask how much warranty is left and whether it transfers. Comparing the range shown at full charge with that of the same model when new also gives a rough idea.

What is battery health (SOH)? EV battery lifespan and how to check it

SOH (State of Health) is the energy a battery can hold today compared with when it was new. EV batteries lose around 2% of their capacity a year on average, leaving roughly 80% after 8 years. Here is how to find your SOH and how to make the battery last longer.

By: Şarj Rehberim · Updated: 2 November 2026 · 6 min read

Short answer

SOH (State of Health) is the energy a battery can store today as a share of its capacity on the day it left the factory. 100% means a new battery; a 60 kWh battery at 90% SOH now holds about 54 kWh, and the range shrinks by the same proportion.

According to a 2026 study by telematics company Geotab covering more than 22,700 electric cars, batteries lose an average of 2.3% of their capacity a year and are at an average SOH of 81.6% after 8 years. In other words, the battery is expected to last the life of the car.

Sources (as of 2 November 2026): Geotab: EV battery health (2026)

Why does a battery lose capacity?

Every charge and discharge causes small chemical changes inside the cells, and some of the lithium becomes permanently unusable. The loss is a little faster in the first year, then slows down and continues almost in a straight line for years.

The main factors that speed it up: leaving the battery at a very high or very low state of charge for long periods, parking in the sun in a hot climate, very frequent high-power DC charging, and models with weak battery thermal management.

How do you find out the SOH?

The car's menu: some models show battery health or usable capacity on screen.
An authorised service report: the service centre can measure the battery's SOH with a diagnostic tool and give you a written report. Ask for this report when buying used.
OBD-II reader and app: on some models, a reader plugged into the car's diagnostic port can read the SOH and cell voltages.
Your own charging records: as you log each charge's start and end percentage and the kWh you took in Şarj Rehberim's Charging Log, the Battery Health card calculates usable capacity from your own data.

How much loss to expect over the years

The table assumes an average loss of 2.3% a year; individual cars can do better or worse depending on use, climate and model.

Car's age	Average SOH	Left in a 60 kWh battery
New	100%	60 kWh
2 years	≈ 95%	≈ 57 kWh
4 years	≈ 91%	≈ 54.5 kWh
6 years	≈ 86%	≈ 51.5 kWh
8 years	≈ 82%	≈ 49 kWh

What does the battery warranty cover?

On most electric cars sold in Türkiye, the battery warranty is 8 years or 160,000 km (whichever comes first), and a drop in capacity below 70% within that period is usually covered. The term, mileage and capacity threshold vary by brand; check your car's warranty document.

Warranty claims are often settled by repairing or replacing faulty modules rather than replacing the whole battery. On a used car, ask whether the warranty transfers to the new owner.

Making the battery last longer

In daily use, keep an NMC battery between 20% and 80% or 90%; with LFP, follow the manufacturer's advice (usually 100% regularly).
Do not leave the car at 100% for days; charge to 100% before a long trip and set off soon after.
Do not leave the battery below 5% for long periods.
On hot days, park in the shade or in a covered car park if you can.
DC fast charging is normal use, but doing your daily charging at home or at an AC station puts less strain on the battery.
If you will not be using the car for a long time, leave the battery at around 50%.

Frequently asked questions

How many years does an EV battery last?: The average loss is around 2% a year, leaving about 80% of capacity after 8 years. At that rate the battery is expected to stay usable for 15–20 years. Most manufacturers give an 8-year or 160,000 km warranty.
At what SOH does the battery need replacing?: There is no fixed limit; a battery at 70–80% SOH keeps working, just with less range. The warranty usually covers a drop below 70% within 8 years.
Does DC fast charging damage the battery?: Occasional DC charging is normal use, and the car protects the battery according to its temperature. Doing all your charging on high-power DC all the time can speed up the loss somewhat; charging at home day to day is best.
How do I check the battery on a used electric car?: Ask an authorised service centre for a written SOH report, and ask how much warranty is left and whether it transfers. Comparing the range shown at full charge with that of the same model when new also gives a rough idea.

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