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There are currently two mainstream standards for measuring the range of pure electric vehicle lithium batteries.
The first is the 60km isokinetic range test. The range tested in this way is very high, but it is too idealistic and has no real reference significance.
The second is the NEDC test standard. This test standard is a bit complicated to explain. Simply put, a NEDC cycle consists of four urban conditions plus one suburban condition, and the entire NEDC cycle is about 11 km long in total, simulating the real driving conditions of the vehicle as much as possible. Therefore, the NEDC test results are more informative for consumers.
The test results obtained under the NEDC test standard are still close to idealistic and may be inaccurate in relation to the actual range. For consumers who are waiting to buy, and for car owners who often have to deal with charging and mileage calculation problems, the reference value is greatly reduced. Therefore, it is understandable that car companies are being questioned about the "false mark", but objectively speaking, it is better to say "false test" rather than "false mark", because the official test standard is already different from the real use There is a large gap between the official test standards and the real working conditions.
The main reason why the actual range of pure electric vehicles is lower than advertised by the manufacturers is that there are many different descriptions of range, which involves the standard of testing range, because most lithium battery manufacturers use isochronous range in order to improve the range, which means that the test is conducted at the most energy-efficient speed range of pure electric vehicles, so that a range can be obtained, but in practice it is impossible to keep the range at the same speed. However, in practice it is not possible to drive at the most energy efficient speed all the time, so this test does not correspond to the actual usage scenario.
In addition, the air conditioner and other electrical equipment in the car consume power, so the range of a pure electric car will be shortened when the air conditioner is switched on, and the high speed of a pure electric car will also consume more power, so running at high speed is more stressful for a pure electric car.
As soon as the electric car lithium battery starts to charge and discharge, the positive and negative electrodes and electrolyte will be stimulated by the chemical reaction to be consumed, the positive electrode ruptures, the negative electrode collapses, the electrolyte decomposes, the substance to store and transport lithium ions becomes less and cannot be replenished, and the available capacity of the lithium battery is reduced. The electric energy storage of pure electric vehicles is the battery, most of the current batteries are lithium batteries, and lithium batteries for the ambient temperature requirements are relatively high, in colder weather, the activity of lithium batteries will be reduced, so the winter range and will produce a certain reduction.
The most suitable working temperature for lithium batteries in electric vehicles is 15-35°C. If this temperature range is exceeded, the capacity decay will be significantly accelerated. In the winter in the north, the temperature of the lithium battery can be as low as -10°C, while in the summer, the temperature and lithium battery heating dual role, the lithium battery temperature can reach 60°C. According to the experimental report proves that the same lithium iron phosphate battery, working continuously at 55°C, the life is only 1/7 of that at 25C, and at -10° C, the life is only 1/10.
How to improve the power lithium battery electric car range?
① Don't overcharge, because the resistance increases in winter, the corresponding storage capacity will be reduced, so the longest charge in summer can reach 12 hours, but in winter, don't exceed 8 hours, is 6 hours can, or it is easy to cause bulging.
② The faster the electric car runs, the faster the energy consumption of the lithium battery will also increase, long-term high-speed riding will greatly deplete the original level of battery power. So it is important to keep the speed as low or even as possible when driving to be able to ensure the range of the electric car.
③Check the tyre pressure frequently to keep the tyre pressure at the correct level, which must be checked every fortnight or at least once a month. Incorrect tyre pressure can cause power consumption, short driving range, reduced driving comfort, reduced tyre life and reduced driving safety.
Conclusion: As more and more lithium battery manufacturers join the camp of lithium-electric vehicles, more and more tricks to serve lithium batteries, the future of lithium batteries for electric vehicles will become better and better, and the range will become longer and longer.