To avoid weight, size and cost constraints, on-board integrated charging devices use the traction system components. The hardware of traction system can work as functions of three bridges rectifier, single-phase PFC and so on. And the charging mode and traction mode of EVs operate in different time. So we can consider using the hardware of traction system to reconstruct a charger. The inverter can work as a rectifier and DC/DC converter can realize buck function in charging mode. Even the motor windings can be used as the grid-side filter inductors or an inductor in DC/DC converter by reconstructing the windings. Additional components may be needed to realize some functions in charging mode. When the motor windings and traction system are integrated into a charger, the weight, size and cost of on-board charger reduce. While, the integrated charger has some disadvantages, such as, the motor maybe rotates in charging mode, the charging power will be limited by the traction system. And the single-phase integrated charger has a problem that dc-side exists second harmonic ripples. The voltage ripple in dc-side is suppressed by a large capacitor or additional components. This paper introduces the topologies of on-board integrated charger for EVs. And a new single-phase integrated charger is proposed which can suppress the second harmonic ripple. The proposed system only needs a small additional capacitor and inductor. The paper is organized as follows. In Section II, the overview of integrated charger is given. Three groups including DC/DC converter, switched reluctance motor and alternating current motor are discussed respectively. A novel single-phase integrated charger based on AC motor is proposed in Section III. The operation of system is analyzed in detail. The experimental results are given in Section IV. Section V gives a conclusion.