Recently, the use of various mobile device such as electric bicycles is rapidly increasing due to the environmental pollution caused by the use of fossil fuels. As a power source for mobile which are free to move, the use of the battery is becoming common and a battery system having various voltages and capacities matching the characteristics of the equipment is used. However, most mobile devices require a dedicated charger, have disadvantaged that the charger must be accompanied at all times for charging. Therefore, this paper proposes a charging topology that can deal with various voltages and capacities of battery for mobile. The proposed charging topology is a multi-level charging topology using a dual voltage source and in order to reduce the current ripple rate according to the charging voltage, we applied the switching variable method according to the charging voltage level setting. We also verify the validity of the proposed topology through simulation using Psim and prototype for experiments.