1. New energy vehicles are the development trend of automobiles at present. However, due to the basic charging facilities and the cruising range of pure electric vehicles, the sales of electric vehicles have not gone up. Of course, major car companies are also adding the cruising range of their own electric vehicles or working hard on charging methods through technical iteration.

2. Limited cruising range and long charging time seem to make new energy sources enter a trough. How can we solve these problems? Adding battery packs to expand the cruising range of electric vehicles; Or improve battery technology and increase battery capacity; Or it can increase the charging efficiency of electric vehicles and shorten the charging time … … Among them, shortening the charging time is a relatively easy technology to realize at present.

3. The charging piles currently built support two charging modes: slow charging and fast charging! This is like charging our mobile phone. There are two modes: fast charging and slow charging. In fast charging mode, the battery can be fully charged quickly, at least 40% faster than slow charging. The car charging here is a similar concept, but it is much more efficient than the mobile phone.

4. However, what riders want to know here is that fast charging and slow charging are two concepts. Slow charging is AC charging, and the full charging time is generally 6-8 hours. In this charging mode, the battery is least damaged. Fast charging is an emergency charging method, which uses high-power DC charging (also AC fast charging). The voltage of this DC charging is generally greater than the battery voltage. It is necessary to convert AC into DC through a rectifier device, which puts forward higher requirements for the voltage resistance and protection of the power lithium battery pack. The charging current is large, which is ten times or even dozens of times that of the conventional charging current. A large number of electrons flow from the positive electrode to the negative electrode at a very high speed. The fast charging time usually takes 30 minutes to charge 80% of the electricity. Some car companies have made breakthroughs in technology and can charge 80% of the electricity in 5 minutes! This charging efficiency is really scary, but the question is also coming. Will it affect the car battery if it is charged so quickly? After all, the battery of an electric car is equivalent to three parts of an ordinary car.

5. In theory, it will affect the battery. After all, fast charging will reduce the cycle charging life of the battery, because the battery is converted into electrical energy through chemical energy, and charging is a reverse chemical reaction. Frequent fast charging will reduce the reducing ability of the battery and reduce the charging cycle times of the battery.

6. In order to alleviate the negative use brought by fast charging, BMS power management system is a very important component in electric vehicles. As far as electric vehicles are concerned, BMS is the core component of fast charging. The important purpose of BMS is to intelligently manage and maintain each battery cell, prevent the battery from overcharge and overdischarge, prolong the service life of the battery and monitor the state of the battery. For example, when you charge a new energy vehicle quickly, BMS can control the input current and voltage to reduce the damage to the battery as low as possible, so these damages can be ignored in a limited time, which shows the importance of BMS on the battery system. In addition, the batteries are all in groups, and some battery packs may not be fully charged under protected conditions during fast charging, and the performance of these battery packs will be degraded after long-term fast charging.