An electronic overload relay includes a microcontroller having an internal random-access memory (RAM) in which a motor thermal model is stored. The microcontroller is coupled to a power supply having a bulk storage capacitor. In response to a trip or stop condition of a protected motor, the thermal model is maintained in the RAM with no timing or decrementing. When the motor restarts, the microcontroller calculates a change in capacitor voltage to estimate the motor stop duration. The thermal model is decremented based on the estimated duration.