Abstract: A battery charger comprising an indicator unit which has control switch and indicator lamps, and three charging slots for charging a variety of batteries of different size and specification, wherein one of the charging slots has vertical guide rails for holding the battery inserted therein and positive and negative charging pins and charging terminals, each of the other two charging slots has plate springs and wire spring for holding different size of battery in charging position and charging pins or charging strip springs for charging the battery inserted therein.