An electric soap dispenser that includes sensors for detecting the presence of an object. The dispenser can be configured to dispense an amount of liquid soap, for example, upon detecting the presence of an object. The dispenser can include various features for enhancing the performance thereof. For example, the dispenser can include an additional button for manual operation of the pump. Additionally, the dispenser can detect the voltage of a power supply and compensate for a drop in voltage of the power supply so as to produce more uniform dispensations of the liquid product.