How many days of autonomy does an off-grid system need?

ModX2 Q5.3 and hub C2. [days of autonomy off grid] AS/NZS 4509.2 guidance: 2 days with automatic generator control, 2–3 days manual, 4–5 days with no generation backup. The governing input is the maximum contiguous low-solar run at your site in the worst month, at end-of-life battery capacity.