The endurance of new energy vehicles has always been one of the indicators that car owners are most concerned about. Nowadays, the sales of pure electric new energy vehicles are rising with the support of policies, but they are still rare on highways. In other words, compared with traditional fuel vehicles, its travel radius is still a problem. Even if the high-speed service areas are mostly equipped with fast charging stations, the time cost and "shortened" battery life cannot be accepted. Today, "E Chehui" will discuss with you in depth why the battery life of pure electric new energy vehicles is shortened at high speeds.

How do pure electric vehicles "energy-saving"?

Compared with traditional fuel vehicles, the efficiency of the electric motor itself is far superior to that of fuel vehicles. There is no doubt that the thermal efficiency of the mainstream electric motors on the market can reach between 80% and 90%, while the traditional engine has the highest thermal efficiency -41%, most of them are around 37%. Compared with traditional fuel vehicles, the electric motor can work completely "on demand". It consumes electricity as the vehicle speed changes, and in some cases can recover electricity; while fuel vehicles have idling speeds and cannot stop working when the accelerator is released.

In view of the relatively more stop-and-go road conditions in big cities, pure electric vehicles consume the least energy when the average speed is low. It is worth mentioning that the energy-saving methods of pure electric vehicles are similar to the current mainstream Accord Hybrid and Toyota Hybrid. These two sets of hybrid system engines are rarely directly involved in driving the wheels. They are basically based on electric output, and the engines are either not working or working in the best efficiency range.

Why is the high-speed cruising range shortened?

As discussed with you above, on urban roads, the efficiency of pure electric new energy vehicles relies on the "less intervention + recycling" approach to save energy, but highways have become a completely opposite situation. We all know that the constant speed range XXX kilometers claimed by many manufacturers are all run on the bench test machine, and it is almost impossible to drive at the speed of 60km/h. Therefore, even if there are few high-speed runs, this number is far from the actual value. In high-speed road conditions, pure electric new energy vehicles face more problems. Let's take an example one by one below.

Wind resistance is a fairly common factor among them. As the speed of the vehicle increases, the wind resistance of the vehicle will increase exponentially. In most pure electric vehicles, the location of the battery will disturb the air in the chassis, so the impact will be greater than that of fuel vehicles. The single-speed gearbox is also one of the culprits. Because there is only a gear ratio equivalent to about third gear of a fuel car, the disadvantages appear at high speeds. In addition, the weight of the vehicle and the use of tires will also play a role in the endurance.

In addition, there are some individual phenomena, such as the reduction of NIO's cruising range, mostly due to the ineffective battery management system (BMS). In a complex battery pack, some battery cells consume too much energy, which will reduce the discharge capacity of the entire battery pack. To give the simplest example, using two batteries together, one new and one old, will reduce the use time by more than half compared to two new batteries.

To sum up, there are still many pain points in the current battery life of pure electric new energy. High-speed road conditions + low temperature are the worst combination. Not only the battery discharge is less, the heating in the car also further consumes electricity. However, with the popularization of the new WLTP test method in China, car companies must find ways to increase the battery capacity and the efficiency level of the entire system. The gradual decline policy will further promote car companies to reduce costs and increase battery life.