Battery health — how to make your battery last longer
The battery is the most expensive component of an EV, and many EV owners wonder how long it actually lasts. The good news is that modern EV batteries in 2026 are robust and hold up well over time — as long as you treat them right. In this article, we explain what battery degradation is, what's normal, and how you can care for the battery to preserve its capacity for many years to come.
What is battery degradation?
All lithium-ion batteries gradually lose capacity over time. This is called degradation. It means that a battery that gave you 400 km of range when the car was new might give you 380 km after a few years. This process is completely normal and unavoidable, but the rate can be influenced by how you use and charge the car.
Factors that affect battery health
Charge level — avoid the extremes
The most important factor you can control is how much you charge the battery. Lithium-ion batteries thrive best in the middle range — neither completely full nor completely empty.
Daily use: Keep the battery between 20 and 80 percent. Most EVs allow you to set a limit for daily charging, for example 80 percent. Use this function.
Road trips: For long-distance driving, it's perfectly fine to charge to 100 percent occasionally. The important thing is not to leave the car fully charged for extended periods. Charge to 100 percent just before departure, not the evening before.
Fast charging — use in moderation
DC fast charging (CCS) puts more stress on the battery than regular AC charging. The high power generates heat, and heat is the battery's biggest enemy. This doesn't mean you should avoid fast charging, but it shouldn't be the only way you charge.
Rule of thumb: If you primarily charge at home with AC and use fast charging on road trips, there's no reason for concern. Problems only arise with very frequent fast charging — for example, daily fast charging over a long period.
Temperature — the hidden enemy
Extreme temperatures are harmful to batteries. Both intense heat and severe cold negatively affect battery health over time. The car's battery management system (BMS) does its best to protect the battery, but you can help:
- Park in the shade in summer and in a garage in winter.
- Avoid fast charging right after long driving in extreme heat — let the battery cool down first.
- Leave the car connected to a charger in extreme cold so the BMS can keep the battery at temperature.
Driving patterns
Aggressive driving with frequent hard acceleration and abrupt braking drains the battery faster and generates more heat. Smooth driving is not only more energy-efficient — it's also better for the battery's long-term health.
How to check your battery's health
Most EVs display some form of battery health information. Here are the most common ways to check:
The car's own system
Many EVs show the battery's state of health (SoH) in the car's menus. Some display it directly, while others require going into the service menu. Check the owner's manual for your car.
Third-party apps
Apps that can read the car's OBD data often provide more detailed information about the battery's condition. These can show degradation in percent, number of charge cycles, and more.
The service workshop
During servicing, the workshop can run a thorough battery diagnostic that gives an accurate picture of the battery's condition.
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Myths about battery health
"I need to fully drain the battery before charging"
Wrong. This applies to old nickel-cadmium batteries (memory effect), but is directly harmful to lithium-ion batteries. Don't let the battery regularly go below 10 percent.
"Fast charging destroys the battery"
Exaggerated. Moderate use of fast charging is completely unproblematic. The car's BMS protects the battery from overload. It's only with very frequent, daily fast charging over a long period that it can have a noticeable effect.
"The battery is ruined after 5-6 years"
Wrong. Data from hundreds of thousands of EVs shows that modern batteries hold up very well. Most have over 85 percent capacity after 8-10 years. The battery will likely last longer than the rest of the car.
Practical tips summarised
Here are the most important measures for good battery health:
- Charge daily to 80 percent — set this as default in the car's settings.
- Avoid leaving the car at 100 percent for extended periods.
- Use home charging as your primary charging method for daily use.
- Fast charge with a clear conscience on road trips — that's what fast chargers are for.
- Park in a garage when possible, especially in extreme heat or cold.
- Drive smoothly and actively use regenerative braking.
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Battery warranty — what's covered?
Most manufacturers offer a battery warranty of 8 years or 160,000 km, with a guaranteed minimum capacity of 70 percent. Some manufacturers have expanded this in 2026:
- Several brands now offer 10-year battery warranties.
- Some guarantee 75-80 percent capacity instead of 70 percent.
- The mileage limit has increased to 200,000 km with several manufacturers.
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Frequently asked questions
How much capacity does an EV battery lose per year?
Normal degradation is 1-3 percent per year for modern EV batteries. The exact rate depends on driving patterns, charging habits, and climate conditions. Cars that are primarily charged at home with AC charging and kept between 20-80 percent will typically be at the lower end of this range.
Is it harmful to charge to 100 percent?
Charging to 100 percent occasionally is unproblematic. What can harm the battery is leaving the car fully charged for extended periods — for example, several days. For daily use, it's recommended to set the charge limit to 80 percent and only increase it when you need full range for a long trip.
How many charge cycles can an EV battery handle?
Modern EV batteries are designed for 1,500-3,000 full charge cycles. A full cycle is from 0 to 100 percent, but daily charging between 20 and 80 percent is only 60 percent of a cycle. In practice, this means the battery can handle many hundreds of thousands of kilometres.
Does cold permanently affect battery lifespan?
Short-term exposure to cold temporarily affects performance and range but does not cause permanent damage. However, long-term storage in extreme cold without being connected to a charger can negatively impact battery health. Park in a garage and keep the car connected during cold periods.
Can a degraded EV battery be replaced?
Yes, EV batteries can be replaced, but it's rarely necessary. If the battery degrades below the warranty level within the warranty period, it's covered by the manufacturer. After the warranty period, battery replacement can be expensive, but battery prices are steadily falling. In 2026, we're also seeing more and more workshops offering repair of individual battery modules, which is far cheaper than replacing the entire pack.
Kilder
- Battery University — Lithium battery longevity best practices
- Geotab — EV battery degradation study (6,000+ vehicles analyzed)
- Recurrent Auto — Real-world EV battery degradation data
- Elbilforeningen — Norwegian EV Association — battery warranty information