An expedited preflight readiness system for aircraft includes a power source having one or more battery modules for storing electrical power. An integrated controller is electrically and communicatively coupled with the power source for monitoring and controlling the power source to provide electrical power to aircraft subsystems. A mobile device is communicatively coupled with the integrated controller for communicating instructions to the integrated controller for initiating preflight readiness of the aircraft and for monitoring preflight readiness. A method for preconditioning an aircraft includes determining a state-of-charge of an APU and activating an environmental control subsystem for preconditioning the aircraft by adjusting a current temperature according to a preconditioning profile based on one or more of a target temperature, a target time, the current temperature, an outside air temperature, an amount of energy, and a state-of-charge of the APU.