How does hot weather affect electric cars?

How hot weather affects electric cars is a matter of concern to many EVs-loving customers. Owners need to understand the effects of hot weather and immediately take measures to maintain optimal operating conditions for electric vehicles. 

1. How does hot weather affect electric vehicles?

Hot weather can cause many negative effects on electric vehicles. Understanding the effects of hot sun on electric vehicles below can help users take measures to prevent and overcome them in time.

1.1. Battery charging speed

In fact, lithium-ion batteries work best in the temperature range of 68-77 degrees Fahrenheit/ 20-25 degrees Celsius. Excessive heat will cause the electronic components in the battery to degrade faster. At the same time, when the point of overheating is near, the charging rate of the battery will decrease. This is because the battery management system (BMS) has adjusted the charging speed according to the temperature of the battery to prevent overheating. Even charging can be paused for safety while waiting for the battery to cool down.

1.2. Battery cooling system

Depending on the cooling system on each electric vehicle model, the battery will not be affected by the same temperature. Using liquid cooling is more efficient than using forced air. Therefore, vehicle owners should check the vehicle’s cooling system and make appropriate cruise adjustments in hot weather conditions.

1.3. Driving range

Besides hot weather also heavily affects driving range. According to the results of a study by the American Automobile Manufacturers Association (AAA), when the outdoor temperature is 95 degrees Fahrenheit/35 degrees Celsius and the air conditioner is used, the driving range is reduced by about 17%. However, different electric vehicles will be affected differently by extreme weather. The lower driving range might affect the distances between each charging time as well as add-up to the total charging bills.

1.4. Tire

Hot weather can have a big impact on tires, reducing reliability and safety when traveling. In addition, overinflated tires in the summer can cause a tire explosion when the temperature is high or the car is exposed to the sun for a long time.

1.5. Battery life

Electric vehicle batteries also have a certain lifespan and degrade over time like any other battery. However, some bad situations can accelerate the rate of battery degradation. The results of a study of 6,000 electric vehicles showed that battery life degrades faster in hot climates than in temperate climates. In addition, the battery degradation rate is even faster if car owners in hot climates regularly use the fast charger. Because fast battery charging uses accelerated current, it will generate higher heat levels than usual.

2. Notes to take care of electric cars in hot weather

Electric car owners should know 6 tips for car care in hot weather below to ensure the car always maintains the most optimal operating state to avoid hot sun effects on electric cars.

2.1. Only charge the battery up to 80%

Most manufacturers recommend that users only charge electric cars to a maximum of 80%. Electric car batteries are self-optimizing so they don’t need to be charged to 100%. Occasionally, users can choose to fully charge if planning a long trip. However, charging to 100%  frequently during summer days will cause the battery to overheat and accelerate the degradation of lithium battery cells. From there, the electric vehicle battery will lose its original charging speed.

In fact, users can extend electric car battery life by limiting the number of full charges. Modern chargers and electric cars are often designed with smart features that allow the user to determine the battery charge level to limit full charge.

2.2. Parking in the shade

Hot weather can have a negative impact on the life and charge rates of lithium-ion batteries in electric vehicles. Therefore, vehicle owners should park in the shade if possible. In the absence of shade, the driver should use some tools such as sunshade, insulating film for the windshield to reduce the temperature in the car.

In particular, vehicle owners should limit fast charging at uncovered stations, because the high intensity current combined with the high temperature of the weather will cause the battery to degrade quickly. Therefore, owners should prioritize slow charging in summer and limit parking in the sun.

2.3. Using preconditioning

The electric vehicle’s pre-conditioning feature allows the driver to adjust the temperature that warms or cools the battery and cabin before the vehicle starts moving. To use this feature, users need to access the pre-conditioning on the infotainment screen of the electric car or via a connected smartphone app depending on the vehicle model.

Pre-conditioning works best when the car is plugged in to charge, drawing energy directly from the mains. So the battery life of electric cars will not be affected.

2.4. Use “Eco” mode while driving

Most electric cars have an “Eco” driving mode driver to improve vehicle performance. This mode can automatically control energy saving up to 10%. Using Eco driving mode on long summer journeys will significantly save the vehicle’s operating range, as electric cars use more energy when emitting heat. That means helping electric cars limit the number of charges, thereby extending battery life.

Although Eco driving mode will limit some of the functions of the electric vehicle, it is a useful way to save energy. In addition, users can take other measures to reduce rapid battery drain such as regenerative braking, which allows the vehicle to recover energy by taking off the accelerator and allowing the vehicle to slow down without pressing the brake.

2.5. Avoid travelling between midday to 3pm if possible 

When the temperature rises, the devices on electric cars can overheat and consume more energy than usual. The period between noon and 3 p.m. is usually the hottest timeof the day. Therefore, users should limit driving during this time frame. Using an electric car in cooler times can significantly reduce energy usage.

2.6. Check tires before moving

Electric cars are generally heavier than internal combustion engine (ICE) models because of the design of the battery pack. Therefore, owners need to pay attention to monitor tire pressure when driving electric cars, especially in hot weather. If the tire is not inflated enough, it will reduce the performance of the vehicle, even cause a tire explosion, threatening the safety of both the driver and passengers.

Owners can purchase a tire pressure monitoring system for convenient regular checking. Users should inflate the tires according to the vehicle’s specifications, and take the car to repair to have the “tire scale” technique.

3. Other Tips and Tricks to overcome the effects of hot weather on electric vehicles

Facing intense heat is not only a challenge for people but also for vehicles. In the long run, frequent exposure to high temperatures can damage and accelerate vehicle aging. Therefore, owners need to take some measures to overcome the impact of hot sun on electric vehicles, ensuring the durability of the car.

Keep the cabin cool

Drivers should park in the shade to keep the cabin cool and reduce the impact of heat on other components. If you have to park in the sun, the vehicle owner should stick a sunshade on the window or use an insulating film to limit the impact of the hot sun on the electric vehicle. Besides, users should open the window slightly down to help better ventilation and suck out the hot air inside the cabin. However, vehicle owners should not lower the windows too much, as this can pose safety risks to occupants.

Air conditioner maintenance

The air conditioning system of electric cars works most on hot days. Because normally in summer, the air conditioner usually takes quite a long time to cool the cabin. Therefore, users need to regularly check and maintain the air conditioner to protect and maintain the optimal operating condition of the device.

To reduce the operating load on the air conditioner, when entering the car, the driver first needs to lower the window to let the heat drop. After that, the driver switches to the highest fan mode for a few minutes. When the inside temperature feels right to the outside, the driver should open the windows and turn on the air conditioner.

Tire pressure monitoring

Tires are one of the parts that are easily damaged in the summer but often neglected. This can cause costly repairs and replacements when the tires are damaged faster, and at the same time does not ensure the safety of the driver when participating in traffic.

Softer rubber is more prone to failure, so poor tire pressure management on a hot day can cause tire damage. On rough terrain, this can even cause a tire blowout. Therefore, car owners need to decrease the pressure by 3-5psi and keep a close eye on the tires in the summer. In addition, vehicle owners should also prepare and regularly check the spare tire pressure.

Radiator maintenance, cooling water replenishment

When cars are over three years old, car owners need to have their radiators serviced and checked for leaks. In addition, vehicle owners should ensure that the correct coolant is used for optimal cooling efficiency, helping to prolong the life of the engine. In fact, one of the common causes of electric vehicle breakdown in the summer is that the engine overheats due to not maintaining the required amount of coolant.

When electric vehicles operate in hot weather, the engine compartment can reach quite high temperatures. Replacing parts in the engine compartment when a specific level of wear is reached is essential to being able to combat the effects of heat on electric vehicles. In particular, hoses and some parts made of rubber are the parts that need to be replaced when they wear out, because the hardened rubber hose is easy to break.

Protect car paint

A good coating can protect electric vehicles from overheating. This is because the paint has formed a protective waxy layer and significantly reflects the heat of the sun. So, if possible, car owners should polish their electric cars before summer with a clear polish.

Troubleshooting 12V battery related problems

Excessive heat in the summer can shorten the life of the battery because the liquid inside the battery evaporates more quickly. Therefore, to limit evaporation, car owners should regularly check and refill the battery with distilled water, ensuring it is maintained at the specified level between MIN and MAX. In particular, users should only add distilled water to ensure the proper concentration of solution in the battery is maintained.

For dry batteries, car owners should regularly check through the “battery indicator” on the battery cover. In which, if this part is green or blue, the battery is still in good working order; white color is in need of additional charging. And if this part appears black or red, it means the battery needs to be replaced.

(*) The information in this article is for reference only.