A battery pack including: a nonaqueous electrolyte secondary battery
including an external connection terminal; and 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 in a range of 0 to 60.degree. C., Q is
8 (.degree. C./C), and A is a discharge rate (C) of the nonaqueous
electrolyte secondary battery in a case where a current required for
discharging a nominal capacity of the nonaqueous electrolyte secondary
battery in one hour is 1C, and is within a range of 4C to 7C.