I know on my Mastiff and Bulldog bagger they use the same battery, not sure about your k9 tho. But I wouldn't trust just any old bike battery. I've heard and read horror stories on this forum site from ppl using cheap batteries and also from using expensive ones supposedly rated at 550 cca. Ican tell you that I have used drag specialties batteries and usually get about a year to 2 years out of them on the Mastiff but I'm not one to use a trickle charger everytime the bike is parked either, but the bagger bulldog i do use the trickle charger everytime its parked because if not within a week the battery is so weak it wont start the bike. the difference between the 2 ones carb and the other fuel injected with a radio that has the memory wire connected. But mine use a group 20 series battery and the last one i bought was a Duracell 310 cca for both bikes from batteries plus for I think about 125 bucks and it seems to be doing a great job so far.