NOVELTY - The secondary battery (190) has a battery unit (100) that has a battery cell (110) and a protruding lead tab (120). A frame case (150) supports the battery unit. The frame case has a first support portion (151) provided for the battery cell and a second support portion (152) provided for the lead tab. Connectors (181) perforate connection holes (125) formed in the lead tab. The connection holes of the lead tab include a first connection hole spaced apart from first edge of lead tab by a first width, and a second connection hole spaced apart from second edge of lead tab by a second width.    USE - Secondary battery used as energy source in mobile electronic device and hybrid electric vehicle. Can be used in e.g. digital cameras, cellular phones, laptop computers.    ADVANTAGE - Provides a secondary battery that has improved efficiency due to reduced electric resistance of the charge-discharge path. Ensures simplified manufacture of the secondary battery since the same connection portion may perforate the holder case and the lead tab to be combined with the terminal portion. Ensures improved overall charging and discharging efficiency of the secondary battery due to reduced heat dissipation of the lead tab and reduced resistance of the charge-discharge path. Prevents heat concentration of the lead tab and ensures further improved charging and discharging efficiency of the secondary battery, since the secondary battery can reduce the electrical resistance of the lead tab on which the charge-discharge current is collected.    DETAILED DESCRIPTION - The lead tab protrudes from the battery cell. The connection holes extend in the direction of the second support portion of the frame case. The ratio of the first width and second width with respect to the overall width of the lead tab is designed to be 12.5 percent or more.    DESCRIPTION OF DRAWING(S) - The drawing shows the exploded perspective view of the secondary battery.    Battery unit (100)    Battery cell (110)    Lead tab (120)    Connection holes (125)    Frame case (150)    First support portion (151)    Second support portion (152)    Connectors (181)    Secondary battery (190)