US Patent 8405353 Controller

A controller 10 suitable for controlling a bath lift. The controller 10 includes a rechargeable unit 12 and a first protection unit 14 which measures the voltage and current provided by the rechargeable unit 12. The first protection unit 14 prevents connection to the bath lift when the voltage of the rechargeable unit falls below a lower predetermined limit. A second protection unit 20 is also provided which measures the voltage from the rechargeable unit 12 and detects whether the voltage has fallen below an upper predetermined voltage, and if the voltage has dropped below this level downward movement of the bath lift is not permitted.