<p>The purpose of this research: (1) To investigate battery temperature during charging using battery<br />charger and electrolyte weight reduction in Yuasa lead acid battery 12V 5Ah liquid vented type before giving<br />battery life extender technology (Vitta-Q battery vitamin). (2) To investigate battery temperature during<br />charging using battery charger and electrolyte weight reduction in Yuasa lead acid battery 12V 5Ah liquid<br />vented type after giving Vitta-Q battery vitamin.<br />This research was used experimental method. The experiment was conducted at the Laboratory of<br />Automotive Mechanical Engineering Education Program, the Laboratory of Mechanical Civil Education<br />Program, JPTK FKIP UNS Surakarta and the Laboratory of Mathematics and Natural Sciences FMIPA UNS<br />Surakarta which addressed at Ahmad Yani 200 Kartasura. The instruments which used to test were Delta<br />DT.115K battery charger, Mettler Toledo digital balance, and Perkin Elmer UV/VIS Spectrometer. The research<br />population were Yuasa 12V 5Ah battery with code number YB5L-B and the research sample were 6 Yuasa 12V<br />5Ah batteries with code number YB5L-B with lifetime of approximately 2 years or 20.000 miles. The<br />comparative study descriptive investigation methode was used to analyse the data.<br />Based on this research can be concluded: (1) The measurement on Yuasa lead acid battery 12V 5Ah<br />liquid vented type before giving Vitta-Q battery vitamin during charging using battery charger resulted the<br />temperature 49 oC and weight of electrolyte 209.5 gr in 230.0 gr electrolytes. (2) The measurement on Yuasa<br />lead acid battery 12V 5Ah liquid vented type after giving 2 ml of Vitta - Q battery vitamin per cell during<br />charging using battery charger resulted the lowest temperature 40.3 oC and weight of electrolyte 216.4 gr in<br />230.0 gr electrolytes. (3) The measurement on Yuasa lead acid battery 12V 5Ah liquid vented type after giving<br />3.5 ml of Vitta - Q battery vitamin per cell during charging using battery charger resulted the highest<br />temperature 49.8 oC and weight of electrolyte 208.1 gr in 230.0 gr electrolytes</p>