Portable gas sensor utilizing fault protective battery cap

A battery assembly for use with a battery-powered portable electrical device, comprising:

• (a) compartment means for maintaining the battery within the portable electrical device;
• (b) removable cap means engageable with the compartment means for securing the battery, said removable cap means detachable from the compartment means to facilitate replacement of the battery;
• (c) current path means within the removable cap means for conducting electrical current from at least one terminal of the battery to circuitry within the portable electrical device when the removable cap means is in engagement with the portable electrical device;
• and
• (d) fuse means mounted within the removable cap means and electrically connected interposing a current path defined by the current path means for interrupting continuity of the current path mans if electrical current conducted through the current path exceeds a preselected level.

A fault protective battery cap for use in a portable electrical device powered by at least one removable battery, the battery cap comprising:

• (a) a battery cap body constructed generally of a nonconductive polymeric material;
• (b) first conductor means for contacting a terminal of the battery when the battery and the battery cap are installed in the portable electrical device;
• (c) second conductor means for contacting a conductor of the portable electrical device when the battery cap is installed in the portable electrical device;
• and
• (d) fuse means electrically connected interposing the first conductor means and said second conductor means for interrupting flow of current from the battery if the current exceeds a preselected level, the fuse means further being encapsulated within said nonconductive polymeric material.