§ 23.2525 – System power generation, storage, and distribution.
The power generation, storage, and distribution for any system must be designed and installed to—
(a) Supply the power required for operation of connected loads during all intended operating conditions;
(b) Ensure no single failure or malfunction of any one power supply, distribution system, or other utilization system will prevent the system from supplying the essential loads required for continued safe flight and landing; and
(c) Have enough capacity, if the primary source fails, to supply essential loads, including non-continuous essential loads for the time needed to complete the function required for continued safe flight and landing.