In charging the battery, the fundamental thing is how to regulate the battery charging process in accordance with the characteristics of the battery, while the battery charging characteristics is nonlinear, so it necessary to controll the charging process with fuzzy logic control. Input parameter is the charging voltage and current will be processed by the fuzzy controll. Battery charging process is regulated by three stages namely prefix, normal, and full. The working principle is the input voltage charger will be rectified by the bridge rectifier then scaled and stabeled by the flyback converter to be converted by a buck converter for battery charging peroses. Used for charging battery is sealed lead acid battery that has a non-linear characteristics, the fuzzy controll been able to controll the charging current but still has an error of 95% between the charging current and charging current terget from fuzzy control results, it can happen due to the range between the low and the battery voltage is between 6.3 to 5.4V full range of data obtained it is quite short. while for the range of 7-10V data is almost never attein, and the range of 0-4V data is almost never filled.
Key Word: Battry Charger, Flyback Converter, Buck Converter, Fuzzy Controll, Sealed Lead Acid
