In order to investigate a simple and efficient liquid cooling method for the rectangular Li-ion power batteries used in electric vehicles, the cold plate with serpentine-channel configuration shaped like U-tube is established. Subsequently, the effect of cooling channel number, the layout of channels and inlet temperature of coolant on cooling performance of battery thermal management system are analyzed. The numerical simulation results demonstrate that the layout of channels in length flowing-direction with 5-channels has the most efficient cooling performance. This design can reduce the maximum temperature by 26 degrees C compared with the 2-channels along width flowing direction. And the maximum temperature of cooling system rises with the increase of inlet temperature of the coolant. However, there exists an upper limit on the number of channels and the inlet temperature with the consideration of efficiency and safety of cooling system. The above results will be helpful to design cold plate for thermal management system of Li-ion power batteries. (C) 2018 Elsevier Ltd. All rights reserved.