This device uses a synchronous rectifier to charge the battery from an alternating current network. information about the current voltage state at each moment of the sinusoid is analyzed by the processor. Due to the synchronous rectifier, a sufficiently high charging power is achieved. but at the same time there are quite stringent requirements for the quality of the supply voltage, frequency, and signal shape. Therefore, if the supply voltage does not fully meet the standards, the device may not charge. this has been tested repeatedly on a gasoline generator on different devices. in this case, the way out of the situation is to use an external power supply that can provide the necessary voltage and current. but the charging speed is usually lower.