PURPOSE: To improve high rate discharge performance at low temperature by installing coils comprising shape memory alloy which produces displacement in two directions and has low transformation temperature in a separating wall space of a container in which a plate group is accommodated.

CONSTITUTION: A plurality of shape memory alloy coils comprising Cu-Zn-Al alloy which produces displacement in two directions and has a transformation temperature of -10°C∼0°C are uniformly arranged in a space 3a of a separating wall 3 of a container 2 comprising resin such as polypropylene. A plate group comprising a cathode plate 4, an anode plate 5, and a separator 6 of a fine glass fiber mat is accommodated in the container, and electrolyte is impregnated in a nonfuid state to form a sealed lead-acid battery. Since shrinkage of electrolyte volume at low temperature is compensated by expansion of shape memory alloy 1, the electrode group is maintained in a pressed state. Therefore, low temperature performance is remarkably improved.