Costco has 51R batteries for about $50, which I have used with excellent results. **************A Good Credit Score is 700 or Above. See yours in just 2 easy steps! (http://pr.atwola.com/promoclk/100126575x1221322931x1201367171/aol?redir=http://www.freecreditreport.com/pm/default.aspx?sc=668072&hmpgID=115&bcd =May5509AvgfooterNO115)