The correct battery is called a DIN66, but that is the European number for it. New Volvos also use the same DIN66 with the ears at the bottom (at least my S40 does). But you do not need nearly that much power to start a 144 at moderate temperatures. The reason for the large battery is because in Sweden you have extreme cold and smaller batteries do not last long. Also in the old days you did not have the modern convenience of mains power points in public parking lots so you could not run battery heaters. You needed a strong battery in those cold climates.