Creation of Microbial Fuel Cell of fruit battery for STEM education

A battery generates electricity through chemical reactions, with fruits serving as natural electrolytes that enable ion flow between metal electrodes, resulting in the production of electrical energy. This education kit is designed based on STEM learning used in science experiments for students to explain electricity and electrochemical reactions from the fruit used as electrolytes in the fermentation process, the low $\mathrm{p H}$ since the fermentation time is related to the higher electric current generated. Three local fruits (orange, pineapple and watermelon) with five days fermentation were used in condition. The results show an orange fruit on fermentation time on day five with the highest voltage, current and power values of ${1. 2 5}$ volts, 0.72 mA and 0.90 mW respectively, and the lowest pH at about 3.67. Therefore, the electricity resulting from these fruits indicates the possibility of utilizing such acidic fruit as a battery.