At present, the batteries of new energy vehicles on the market are mainly lithium iron phosphate batteries and ternary lithium batteries. The charging and discharging process of lithium battery is the process of lithium ion migration through electrolyte at the anode and cathode. No matter charging or discharging, lithium ion moves in one direction, so lithium ion can only receive or output direct current. However, both the electricity generated by the power plant and the electricity transmitted in the wires are alternating current. If you want to charge the battery, you must complete the conversion from alternating current to direct current through a rectifier, and the difference between fast charging and slow charging lies in where this rectifier is installed. At present, the slow charging conversion depends on installing a rectifier on the car, but because the rectifier will also generate heat when it works, it will cause heat dissipation problems, so it is afraid to charge too much at once, and the conversion speed of the rectifier on the car will also affect the charging speed. Fast charging is to install the rectifier on the charging pile, so you will find that the fast charging pile is much bigger than the slow charging pile, because there must be a strong rectifier inside. Second, what is the damage to the battery by using fast charge all the time? The answer to this question also needs to be given in combination with the battery quality of the car.
Theoretically, fast charging of new energy vehicles will damage the life of batteries, but this damage is relative to slow charging. If the fast charging times are more, the user can obviously feel that the battery is not working, indicating that there is something wrong with the fast charging setting of this car. In order to achieve fast charging ability, car companies will charge quickly when the battery can't bear it, which will also affect battery life. Third, for example, if the batteries of two cars are the same, the cycle life of 1500 cycles can be guaranteed by slow charging.
However, one of the cars may set the fast charging mode to 15 minutes to charge to 80%, but the fast charging life is only 500 weeks; The other car is set to charge to 80% in 30 minutes, and the life after fast charging can reach 1200 cycles. Then use fast charge as little as possible in the front car, and the fast charge in the rear car will not feel the difference even if it is used frequently. 4. Therefore, some cars will charge fast all the time. After 10w km, the battery health can be above 95%, and some cars will charge fast occasionally. After 10w km, the health is only 89%.
Without knowing whether the fast charging setting of the car is appropriate, if the conditions do not support the installation of private charging piles at home, it is best to charge the car with slow charging piles 2-3 times a month, which is more friendly to the battery and lasts longer.