To provide a nickel-hydrogen storage battery which prevents discharge capacity from varying even if temperature varies among unit cells communicated with each other.

This nickel-hydrogen storage battery 1 is provided with a square-shaped battery jar 3 having a plurality of battery jars which are sequentially connected through barrier plates 5 and the internal spaces of which are in communication with each other, and a group of electrodes 6 formed by laminating a positive electrode plate having a nickel hydroxide and a negative electrode plate having a hydrogen storage alloy absorbing and desorbing hydrogen through a separator. In this battery, a unit cell 2 is formed by storing the group of electrodes 6 in each battery jar together with an electrolyte, and the unit cells 2 are connected in series in the square-shaped battery jar 3. The hydrogen storage alloy having a lower hydrogen equilibrium pressure in comparison with the hydrogen storage alloy of the negative electrode plate in the unit cell 2 having low battery temperatures is used.