An apparatus for error checking in a power supply includes a power module that determines that the power supply is in a self-test condition. The system has a directional coupler arranged at an output stage of a power amplifier in a transmitter and that has outputs directed to an antenna and a receiver, and a reception RF switch arranged at an input stage of a frequency converter in a receiver and that has inputs directed to the antenna and the coupler. A flexible tether is connected to the spout cover and to the cap assembly or the bottle. The protective coating is also being substantially impermeable to oxygen.