Battery cartridge having a recess for detecting misuse and/or recessed terminals

A battery pack comprising:

• a casing having an outer surface and at least two rows for accommodating batteries therein, said outer surface of said casing having a bottom surface and a detection recess formed along a center line of said bottom surface of said casing, and
• wherein columnar batteries are accommodated in two rows in said casing and said detection recess is disposed between said two rows of batteries along said center line of said bottom surface;
• and
• an identification marker disposed along said center line of the bottom surface for indicating that the battery pack was finished in use or that the battery pack was already charged.

A battery pack having a battery accommodated therein comprising:

• a casing for housing said battery, said casing having an upper portion and a bottom portion, a bottom surface of said bottom portion having a concave portion at one end thereof;
• a plurality of electrodes formed in said bottom portion of said casing for electrical connection with said battery, said electrodes functioning as charging electrodes when said battery pack is connected to a battery charger and said electrodes functioning as power supply electrodes when said battery pack is connected to an electrical apparatus;
• a marker slidably disposed on said concave portion of said bottom surface, said marker forming a sliding plate and said marker having an enlarged protruding section at one end thereof;
• a hole formed in said concave portion for receiving the sliding plate of said marker opposite the protruding section;
• and
• an aperture formed adjacent to said concave portion in said bottom portion for viewing the position of said sliding plate;
• whereby said sliding marker slides into said hole when said pack is connected to an electrical apparatus and said aperture visually showing such position thereby indicating that the battery has been used, and said sliding marker is moved in the opposite direction to an opposite position by said protruding section when said pack is removed from a battery charger and said aperture visually showing such position thereby indicating that the battery has been charged.