An uninterruptible power supply comprising: an input to receive input power; a power supply circuit coupled to the input, to convert input power received from the input; a battery coupled to the power supply circuit, to provide battery power to the power supply circuit as an alternative to input power; an output coupled to the power supply circuit, to provide output power derived from at least one of the battery and the input power; a controller, supported by the housing and coupled to the power supply circuit, the controller being configured to: receive, from at least one sensor coupled to the controller, information relating to one or more environmental parameters of the uninterruptible power supply; and adjust one or more test parameters of a battery test based on the received information relating to the one or more environmental parameters, wherein the one or more test parameters includes a time remaining until a next scheduled battery test maintained by a calibration timer, and wherein in adjusting the one or more test parameters, the controller is further configured to increase and decrease the calibration timer based on the received information relating to the one or more environmental parameters; characterized in that the controller is configured to receive the foregoing parameters at fixed time intervals and is configured to adjust the foregoing parameters at the fixed time intervals. an input to receive input power; a power supply circuit coupled to the input, to convert input power received from the input; a battery coupled to the power supply circuit, to provide battery power to the power supply circuit as an alternative to input power; an output coupled to the power supply circuit, to provide output power derived from at least one of the battery and the input power; a controller, supported by the housing and coupled to the power supply circuit, the controller being configured to: receive, from at least one sensor coupled to the controller, information relating to one or more environmental parameters of the uninterruptible power supply; and adjust one or more test parameters of a battery test based on the received information relating to the one or more environmental parameters, wherein the one or more test parameters includes a time remaining until a next scheduled battery test maintained by a calibration timer, and wherein in adjusting the one or more test parameters, the controller is further configured to increase and decrease the calibration timer based on the received information relating to the one or more environmental parameters; characterized in that the controller is configured to receive the foregoing parameters at fixed time intervals and is configured to adjust the foregoing parameters at the fixed time intervals. receive, from at least one sensor coupled to the controller, information relating to one or more environmental parameters of the uninterruptible power supply; and adjust one or more test parameters of a battery test based on the received information relating to the one or more environmental parameters, wherein the one or more test parameters includes a time remaining until a next scheduled battery test maintained by a calibration timer, and wherein in adjusting the one or more test parameters, the controller is further configured to increase and decrease the calibration timer based on the received information relating to the one or more environmental parameters; <EOS>