Nonaqueous electrolyte battery and battery system

A nonaqueous electrolyte battery comprising:

• a positive electrode comprising a positive electrode active material layer comprising lithium nickel cobalt manganese composite oxide;
• a negative electrode comprising a negative electrode active material layer comprising a spinel type lithium titanate;
• and
• a nonaqueous electrolyte having an ion conductivity of not less than 7 mS/cm and not more than 10 mS/cm at 25° C.,
• wherein a capacity ratio p/n is within a range of not less than 1.4 and not more than 1.8, where p is a capacity per unit area of the positive electrode, and n is a capacity per unit area of the negative electrode,
• a thickness ratio Tp/Tn is within a range of not less than 1.05 and less than 1.3, where Tp is a thickness of the positive electrode active material layer, and Tn is a thickness of the negative electrode active material layer,
• a ratio Pp/Pn is within a range of not less than 0.55 and less than 0.8, where Pp is a porosity of the positive electrode active material layer per 1 μm of the thickness of the positive electrode active material layer, and Pn is a porosity of the negative electrode active material layer per 1 μm of the thickness of the negative electrode active material layer.