6 mistakes to avoid to extend electric car battery life

Just like smartphone batteries, today's electric car batteries (mostly Lithium-ion, NiMH) can degrade quickly if you don't use them properly.

If you want to maintain maximum battery performance and longevity, you must practice proper driving and charging habits. Here are six easy-to-avoid mistakes that electric car owners should know.

1. Let the battery "starve" for too long and too often

If you let your car battery drop very low on a regular basis (below 5%) and don't charge it immediately, you're cutting into the life of your battery.

Ideally for daily use you should keep your battery between 20 and 80%.

Do not let the battery get too low before charging.

However, there will always be situations where you might want to ignore this rule. For example, it’s not a big deal if you charge your car to 95% before a long trip and plug it in when you get to your destination with less than 10% to go. As long as this only happens occasionally, there’s nothing to worry about.

2. Leaving the car unused for too long

If you don’t drive much, make sure your car doesn’t sit idle for more than a month. As mentioned above, make sure your electric car maintains a charge between 20 and 80 percent when parked for long periods of time, with 50 to 75 percent being the ideal level.

3. Choose fast charging too often

As electric cars become capable of charging quickly thanks to DC fast charging, like on the Tesla Model 3, many car owners want to take advantage of this as much as possible to save time waiting for charging.

However, regularly opting for fast or ultra-fast charging is not the best idea for extending the life of an electric vehicle battery.

Vinfast VF8 car is charging in normal mode. Photo: Tien Dung

The main issue here is heat. A significant amount of heat needs to be dissipated during fast charging. A good example is fast charging of phones. This can be harmful to battery cells. If you drive a lot and tend to charge mostly at fast charging stations, the battery will often overheat and this can lead to premature damage.

The best solution is to charge slowly until full and only fast charge for everyday and super fast for long trips or emergencies.

4. Drive in a sporty style

Electric vehicle batteries are designed to last a certain number of charge cycles. One cycle is equivalent to one complete charge and discharge cycle. On average, lithium-ion batteries have a charge life of 1,000 to 1,500 cycles. So if you frequently drive in an aggressive, speed-loving manner, you will need to charge your car more often. This will result in a correspondingly shorter battery life.

Modern electric vehicles are equipped with devices that promote more economical driving. Driving in eco mode is not only good for your car’s battery, but it’s also a great way to cut costs by reducing the number of times you need to recharge your battery.

5. Charge when the battery is already hot

Temperature is one of the factors that affect the charging time and charging power for electric vehicles. The maximum charging efficiency of electric vehicle batteries is between 20 and 40°C.

Excessive temperatures (50-70°C) can damage lithium-ion batteries. Like fast charging, long-distance sporty driving generates a lot of heat in the battery. If you then plug your car in to charge (especially fast charging), the battery can reach critical temperatures.

While this tip is valuable for lower-cost vehicles that don’t yet have an effective battery temperature regulation system, Tesla vehicles now have an effective battery temperature regulation system.

6. Park your electric car outdoors

This last point isn’t necessarily a “mistake.” However, if you have another option, you should park your electric vehicle in a covered environment like a garage or underground parking lot.

In extremely hot weather, it is best not to leave an electric vehicle outdoors in the sun. If the vehicle must be parked outdoors and is heating up, it is also advisable to let it cool down before charging.

In winter, while cold weather does not lead to premature battery wear, it does prevent the cells from performing at their optimal level. This is why we see reduced range in electric vehicles during the winter months. However, this does not exacerbate battery degradation.