A controller (11) in a tap timer, having a battery (19) for connected via a charge circuit (23) to selectively charge a storage capacitor C2. The storage capacitor C2 is connected to an actuator circuit (25) to selectively provide power from the storage capacitor C2 to actuate a device M1. A processor (13) controls the actuator circuit (25) according to a pre-programmed schedule or on user demand. The processor monitors various parameters including charge rate of the capacitor C2 in order to determine battery condition, to determine if the processor (13) should next actuate the device (13).
