Abstract: A method and apparatus for charging batteries of the type characterized by entry into a gassing phase just prior to reaching full charge, are disclosed. Means are provided for periodically applying a load across the battery terminals during charging of the battery and for accurately measuring the battery discharge through the load. All signals other than those directly attributable to the battery energization of the load are removed from the measured signal. The isolated load response signal is compared to a predetermined threshold value established for the battery being charged to accurately determine when the battery enters into its gassing phase. Battery charging is maintained following entry of the battery into its gassing phase for a period of time known to return a predetermined overcharge of approximately 5 to 15% to the battery.