want a settings page or just a setting in the settings menu for a difficulty:hard option.

fuel cells will cease to function if the vessel's available EC reaches 0f. This does not include locked tanks.

Additional option is to have an even higher difficulty setting where even if the fuel cell is operational and has fuel it will stall.

A stalled fuel cell is inoperative until it can be jump started.

Reasoning is fuel cells take EC, even if a very small amount, to operate and they cannot operate in a 0 EC environment.