Storage battery system and automobile

A storage battery system, comprising:

• a battery module including nonaqueous electrolyte secondary batteries, each of the nonaqueous electrolyte secondary batteries comprising a negative electrode, a positive electrode and a nonaqueous electrolyte, the negative electrode including a negative electrode layer and a current collector having the negative electrode layer mounted thereon, and the negative electrode layer contains lithium-titanium composite oxide particles;
• a dynamo which forms a regenerative power for charging the battery module;
• a temperature sensor which measures a temperature of the battery module;
• a voltmeter which measures a voltage of each of the nonaqueous electrolyte secondary batteries;
• and
• a charge control unit which controls a maximum end-of-charge voltage V1 (V) of the nonaqueous electrolyte secondary batteries to fall within the range defined in formula (1) given below when the temperature of the battery module is not lower than 45° C. and is not higher than 90° C.:
• 0.85×V0≦V123 0.96×V0 (1)
• where V0 denotes a maximum end-of-charge voltage (V) of the nonaqueous electrolyte secondary batteries when the battery module is charged fully at 25° C.