Charging an electric car with a charger is actually charging the battery of the electric car.
The principle of charging is that when the battery is discharged, DC current and discharge current are used to pass through the battery in the opposite direction to restore its working ability, and this process is called battery charging. When charging the battery, the positive terminal of the battery is connected to the positive terminal of the power supply, the negative terminal of the battery is connected to the negative terminal of the power supply, and the voltage of the charging power supply must be higher than the total electric potential of the battery. Generally speaking, there are two charging methods for charging pile, which are constant current charging and constant voltage charging.
Constant current charging method: Constant current charging method is a charging method to maintain the strength of charging current by adjusting the output voltage of the charging device or changing the series resistance of the battery. The control method is simple, but due to the ability of the battery to accept current is gradually declining with the charging process, to the late charging, charging current is used for electrolysis of water, generating gases, so that the gas is too much, therefore, often choose the stage charging method.
Constant voltage charging method: the charging power supply voltage is kept at a constant value in all charging time, and the current is gradually reduced with the gradual increase of the terminal voltage of the battery. Compared with the constant current charging method, the charging process is closer to the optimal charging curve. Constant voltage fast charging. Due to the low battery electromotive force at the beginning of charging, the charging current is very large, and as charging proceeds, the current will gradually decrease, so only a simple control system is needed.
