If it’s the self contained model look for an Interstate SP-40. It’s 340 cca which is a little more than the standard lawnmower battery. Be sure you have a good size gauge on the wires connecting it all. While mine is not self contained I use that battery with some longer welding cables. It spins over everything from a yammie to a 250 single with plenty to spare. Maintain it properly and they are good for 2 to 3 years.