An overdischarge preventing circuit apparatus according to this invention is an overdischarge preventing circuit apparatus for a nonaqueous electrolyte secondary battery, including a discharge control mechanism which controls discharge of the nonaqueous electrolyte secondary battery when a surface temperature of the nonaqueous electrolyte secondary battery exceeds a discharge control temperature T.sub.1 (.degree. C.) represented by T.sub.1=T.sub.0+QA (1) where T.sub.0 is an ambient temperature (.degree. C.), Q is 8 (.degree. C./C), and A is a discharge rate (C).