Abstract: A multi-purpose battery for mobile phones includes a battery casing and a charging battery unit accommodated in the battery casing. The battery unit has a positive pole connected via a contact "a" of a switching switch to positive poles of a charging contact terminal and a power supply contact terminal. The contact "a" of the switching switch further connects an illuminating element and a press switch to the charging battery unit and negative poles of the charging contact terminal and the power supply contact terminal. The switching switch has another contact "b" connected in series with a buzzer and a high-voltage generator, both of which capable of forming a loop with the charging battery unit when the press switch is pressed. The high-voltage generator is connected to an electric guide rod controllable by a push switch to extend from or retract into the battery casing. All of the above-mentioned components are embedded below an outer planar surface of the battery casing to facilitate operation.