Fuel cell

A fuel cell was an essential component found in a starship's main power core. The collapse of a ship's internal fuel cells resulted in its destruction after several minutes.

The Boslic cargo vessel commanded by Jaheel nearly experienced a collapse of its fuel cells in 2369, during an attempt to forcibly remove the ship from Deep Space 9's mooring clamps. His actions caused his ship's isolation plate to buckle causing the main power core to rupture, threatening a possible collapse of the internal fuel cells. 

Later that year, when the runabout USS Yangtzee Kiang was shot down by an automatic orbital defense system orbiting a moon in the Gamma Quadrant, the ship began losing power. In spite of this, along with the failing of the impulse generator, the ship was still able to maintain fuel cell output at 65%. 

In 2374, B'Elanna Torres had to cancel a fuel cell overhaul on USS Voyager after two of her engineers were out sick.