Abstract: The present unit has a dielectric housing with metal prongs or blades for plug-in insertion into a conventional A.C. power socket, a step-down transformer and a rectifier in the housing, a closely coiled power cord extending from the housing, and a plug at the opposite end of the power cord for plug-in insertion into the usual cigarette lighter socket in a car. A selector switch, either in the housing or the plug, selects the charging rate. An LED or a meter is provided in the plug to indicate visually when the car battery is being charged.