Notes on charging of new energy vehicles
With the vigorous development of new energy vehicle industry, safety has become the key factor restricting the development of the industry. According to the survey data of China Automobile Circulation Association, 72% of consumers think that safety is one of the main factors affecting the purchase of new energy vehicles. When we developed the "ceve regulation", we took the issues of widespread concern of consumers as the starting point, fully investigated the consumers' complaints about the current electric vehicle's endurance, environmental resistance, charging, experience, safety and other issues, and summed up three evaluation dimensions of energy consumption, safety and experience. In the safety dimension, in addition to the accident safety enforced by laws and regulations, the use safety and functional safety evaluation are added. While evaluating the environmental resistance and misoperation resistance of vehicles, we also need to guide consumers to improve their safety awareness and standardize the use habits of new energy vehicles from the perspective of vehicle use.
The new energy class in this issue will focus on the matters needing attention in charging and using new energy vehicles
As a consumer, of course, I hope that the longer the battery life of your car is, the better it will be. If you keep good charging habits, you can prolong its life. Let's have a look.
1. Fast charging or slow charging?
According to the research on battery charging mode of ceve regulation, it is found that for new energy vehicles on the market, whether fast charging or slow charging, the charging principle lies in the process of transferring lithium ion from positive electrode to negative electrode under the action of external electric energy, and the difference between fast charging and slow charging lies in the migration speed of lithium ion in the positive electrode of cell 。 When the continuous charging current is large, the ion concentration at the electrode increases, the polarization of the battery increases, and the internal resistance of the battery increases, which leads to the heating effect. Fast charging means that the charging current is increased. Frequent fast charging will accelerate the polarization of the battery and reduce the battery life. However, don't be too nervous. When using a car at ordinary times, the battery can be polarized at a normal speed by alternating slow charging and fast charging, so as to prolong the service life of the battery.
2. To extend battery life, this problem should be avoided?
Under frequent fast charging and low temperature environment, it is possible for lithium ions to precipitate on the surface to form dendrite lithium. Dendrite lithium will pierce the diaphragm and reduce the battery capacity. When the crystal reaches a certain amount, it will even pierce the cell diaphragm, causing battery short circuit, and in the most serious case, it will lead to vehicle spontaneous combustion.
Therefore, in the daily use of vehicles, it is recommended to reduce the frequency of fast charging when possible, avoid low-temperature fast charging, which can extend the service life of the battery and reduce the safety risk.
How long does the new energy vehicle charge?
Will the charging time of new energy vehicles affect the service life of batteries? Through the interpretation of charging safety requirements for electric vehicles, ceve finds that the power batteries of new energy vehicles on the market can be roughly divided into two types: lithium iron phosphate batteries and lithium ternary batteries. For lithium-ion battery, there is a safe voltage space when charging and discharging. When the battery voltage is lower than the set minimum voltage and continues to discharge, there will be over discharge. The growth of copper dendrite caused by over discharge will cause internal short circuit of lithium-ion battery, thus increasing the probability of heating out of control; when the battery is overcharged, a large number of lithium ions overflowing from the positive electrode will deposit and dissolve on the negative electrode surface The catalyst is oxidized to produce a large amount of heat, which makes the battery temperature rise, and promotes the reaction between solvent and lithium metal to produce more heat and gas, which leads to the combustion of battery pack.
Therefore, in the process of using new energy vehicles, we should grasp the charging time according to the actual situation of vehicles, and grasp the charging frequency with reference to the actual use frequency and mileage. In normal use, when the meter shows low power, it should be charged as soon as possible to avoid battery over discharge; when the meter shows that it is fully charged, it should stop charging to avoid overcharge. Over discharge, overcharge and insufficient charging will affect the performance of the battery, and even cause safety risks.
Through the above introduction, I believe that you have a deeper understanding of the charging and using safety of new energy vehicles. With the continuous innovation and breakthrough of new energy vehicle technology and the continuous improvement and improvement of infrastructure, such as the continuous upgrading and evolution of ceve regulation evaluation system platform, consumers will be more scientific and assured in selecting and using vehicles!
