Automatic Water Filling System of Flooded Lead-Acid Battery for Solar Home System

The Solar Home System (SHS) implementation cannot be separated from the battery, which plays an essential role as an energy storage component. One type of battery that is economical and easy to apply as a battery for SHS is a flooded lead-acid battery. The main challenge in using these batteries is the need to carry out maintenance, namely manually filling the battery with water and keeping the water level in each cell balanced so that the battery’s performance is optimum. Therefore, in this project, a flooded lead-acid battery caps model was developed with a level sensor which can later be implemented as a component of an automatic water filling system. It has been made, designed, tested, and analyzed using a comparison of 3 models of caps with their respective level sensors, namely the caps model with float switch (FS) level sensor, optical liquid (OL) level sensor, and electric current (EC) level sensor. With a 100% effectiveness, 1.71 s delay time, 94.0% accuracy, and a precision rate of 98.1%, the cap model with FS level sensor is considered excellent to other caps models to be applied to the SHS scale automatic water filling system.