The demand for pollution-free transportation is increasing with the demand for electric vehicles (EVs). The EV charging infrastructure is being necessary due to increasing the number of EVs. Therefore, we need effective and economical charging technology for charging EV. However, we do not have those systems where the battery charger itself notifies the battery status of the charger (SOC) of EV. Therefore, in this paper, we design a system that can notify the battery status of the charger. For this purpose, pilot communication can be used between the electric vehicle and the slow charger. The battery SOC is obtained from the voltage range of –11V to –12V by using a pulse wave modulation (PWM) signal with a frequency of 1kHz and an amplitude of ±12Vt.

EV, slow charger, pilot communication, PWM.