There is provided an AC-DC converter circuit (100) for high power charging of an electrical battery. The circuit comprises an input rectifier comprising a first node and a second node. The input rectifier (110) is configured to receive an AC voltage at the first node (112) and provide a rectified voltage at the second node (114). The circuit further comprises a first transistor (120), comprising a first gate node (122), a first source node (124), and a first drain node (126). The first drain node is connected to the second node of the input rectifier. The first gate node is connected to a ground node (170). The circuit further comprises a second transistor (130), comprising a second gate node (132), a second source node (134), and a second drain node (136). The second drain node is connected to the first source node. The second transistor materially corresponds to the first transistor. The circuit further comprises a duty cycle control unit (140) connected to the second gate node for providing the second transistor with a switching waveform. The circuit further comprises an output rectifier (150) connected to the second source node or the first source node. The circuit further comprises an output electronic filter (160) connected to the second source node or an output node (151) of the output rectifier. An AC-DC converter device, a method for charging an electrical battery, and a regenerative braking system is also provided.