Batteries are an important part in photovoltaic systems. They ensure reliability and good-operation of the overall PV system. In this paper, we proposed a method based on the estimation of the solar radiation to check the faults that occur in the lead–acid batteries. At first, the GISTEL (Gisement solaire par télédetection: Solar Radiation by Teledetection) model is chosen as a satellite image approach to estimate the hourly global solar radiation. Secondly, the estimated data are selected as input to check the faults of the lead–acid battery. A simple and effective method is developed to detect the internal resistance effect as well as the overcharging problem during the charging and discharging cycles. The experimental results show the easiness of the proposed method that possesses a good accuracy.