A spa is provided including a frame, a shell mounted to the frame defining a basin for holding water, at least one sensor for monitoring a spa component or water condition, a communications interface including a cellular transceiver, and a battery for providing power to the at least one sensor and to the communications interface when the spa is not connected to a power source. The spa also includes a controller in electrical communication with the at least one sensor and the communications interface. The controller is configured to, while the spa is not connected to the power source, receive information from the at least one sensor, process the received information, and cause the communications interface to wirelessly transmit the processed information to a remote source or central server.