What is the Electric Vehicle Charging Current

The standard charging current for electric vehicles is approximately 15A, with conventional battery charging methods typically employing low-current constant voltage or constant current charging. Rapid charging currents range from 150 to 400A, providing short-term charging services within 20 minutes to 2 hours of parking by delivering higher currents for a brief period.

After the battery discharge is complete, it should be charged immediately with a relatively low current of around 15A. This is referred to as standard charging (or normal charging). Conventional battery charging methods generally use low-current constant voltage or constant current charging, typically taking 5-8 hours, or even as long as 10 to 20 hours.

Rapid charging, also known as emergency charging, delivers higher currents for a short duration, providing quick charging services within 20 minutes to 2 hours of parking, with charging currents usually ranging from 150 to 400A. Conventional battery charging methods often take considerably longer, posing practical inconveniences. The advent of rapid-charging batteries has provided technical support for the commercialisation of pure electric vehicles.

Constant current charging method: This method involves adjusting the output voltage of the charging device or altering the resistance in series with the battery to maintain a consistent charging current. While the control method is straightforward, the battery's acceptable current capacity gradually decreases as charging progresses. Towards the end of charging, much of the current is used for electrolysing water, generating excessive gas. Therefore, staged charging methods are often preferred.

Constant voltage charging method: Here, the voltage of the charging source remains constant throughout the charging period, while the current gradually decreases as the battery's terminal voltage rises. Compared to constant current charging, this method aligns more closely with the optimal charging curve. Rapid charging at constant voltage results in a high initial current due to the battery's low electromotive force early on, which then diminishes as charging proceeds. Consequently, only a simple control system is required.