Abstract: An electronic charging circuit for battery operated appliances has a thermostat in physical, heat transferring contact with a battery pack to be charged, a power resistor in physical, heat transferring contact with the thermostat, the power resistor being connected in series with the battery charger and an electronically timed switch. Because certain types of fast charge batteries must be cooled after relatively rapid discharge, such batteries requiring approximately 10 times longer to reach full charge when overheated than when cooled, the electronically timed switch prevents commencement of charging of the battery pack after a rapid discharge until after the elapse of a selected amount of time sufficient to permit the battery pack to cool.