Whilst basic, its a critical and valid point. It is being made on a forum where shipping, ships, and related engineering issues are not well known (at all).
It does lead to questions about how backup and failover power work on large ships. Secondary generation? Central batteries? Per device battery failover?
Batteries, yes. And there's an emergency generator that runs on diesel (big ships run on "bunker oil") which can be started with batteries or manually.
