A multi-battery charging system for reduced fuel consumption and emissions for an automotive vehicle. The system starts the vehicle with a start battery in a fuel savings manner, removing electrical torque from the alternator shaft, and allows a second (run) battery to provide all or some of the current required by the vehicle loads as a fuel savings measure. The system also utilizes an electrically heated catalytic converter (EHC) and a third (EHC or storage) battery to provide a 3 to 15 second preheat and/or a 20 second current, during vehicle start, to the EHC heater coil, e.g., of a small EHC located in series with a standard catalytic converter for emissions reduction to reduce emissions during start. The start battery is recharged after start and switched out of the system fully charged for future vehicle starts. The run battery is recharged when its charge level drops below a predetermined level with an on board battery charging device powered from a 115 volt or 220 volt ac power line source external to the vehicle.