In this study, the MITSUBISHI PLC (FX2n-32MR) is used to achieve the lead-acid battery monitoring system. The battery is by way of rater and FX-2AD used in charging state. The analog and digital data are transmitted to PLC to get the real-time monitoring and control. During charging, time and voltage keep constant to reach charging optimization condition. In addition, AD590 is used as reference measurement and battery protection in temperature control.