I would stick with the stock battery. For the amount of life that it gives it's worth the extra money imo. I'm on 5 years as of this month *knock on wood*.This is from hdlparts.comBATTERY (YTX20L-BS) 31500-MCA-003AH (replaces 31500-MCA-003) 001 $81.87 http://www.hdlparts.com/fiche_section_detail.asp