In this work, a flexible battery structure is fabricated using soft lithography and three-dimensional (3D) printing technology. Ga_52.5Sn_39.5Zn₈ anode material, Bi₆₇In₃₃ cathode material, and alkaline hydrogel electrolyte are introduced to form the flexible battery. A variety of circuit structures are fabricated to realize the series-parallel integration of different numbers of single cells and achieve the fabrication of batteries with different voltages and powers, with a maximum open-circuit voltage (OCV) of 4.6 V and a maximum output power of 1.193 mW. A reconfigurable soft battery group is proposed, and the regulation of the battery voltage has been realized through the microfluidic perfusion process without the need for an external variable-voltage circuit. We have also fabricated an EGaIn-NaOH microfluidic switch to achieve the control of the light emitting diode (LED). In addition, a wristband with a flexible battery is demonstrated to realize power supply to a liquid crystal display (LCD) with a clock or a temperature sensor.