SECONDARY BATTERY AND SECONDARY BATTERY CONTROL METHOD

A secondary battery is provided with a power generation element, an electroconductive member, an external short circuit, a current detector and an external discharge safety circuit. The power generation element has a unit cell layer that includes a positive electrode, a separator and a negative electrode stacked in that order. The electroconductive member is disposed on one outward side of the power generation element with an insulation member interposed therebetween. A lead wire connects the electroconductive member with the negative electrode tab. The current detector detects whether or not current is flowing to the lead wire. The external discharge safety circuit is provided to short-circuits a path between the positive electrode tab and the negative electrode tab outside the power generation element while current detector detects a current.