LITHIUM SECONDARY CELL PACK, AS WELL AS ELECTRONIC DEVICE, CHARGING SYSTEM, AND CHARGING METHOD USING SAID PACK

摘要

This lithium secondary cell pack is characterized in being provided with a lithium secondary cell, a PTC element, and a protection circuit. The lithium secondary cell includes an electrode body and a non-aqueous electrolyte, the electrode body being obtained by placing a positive electrode and a negative electrode facing each other across a separator. The protection circuit includes a field-effect transistor. The energy density of the lithium secondary cell per volume is 450 Wh/L or more. The current density of the lithium secondary cell is 3.0 mA/cm2 or less. A≤50 m&OHgr; and B/A≤1 (where A (m&OHgr;) is the impedance of the lithium secondary cell, and B (m&OHgr;) is the impedance of the entire circuit unit of the lithium secondary cell pack excluding the impedance A (m&OHgr;) of the lithium secondary cell).