I just found the invoice for my Deka battery while purging some paper work in my den. the purchase date was Mar 8- 2013. Some winters I put it on a battery tender and some I just plain forgot. In either case the batttery has never been removed from the bike and the bike has always sat outside through the winter under a good quality full bike cover Other than when in my garage to be worked on. To this day that battery is still kicking strong. That is over 10 years for a battery that cost me $94.00 at the time which was only $20.00 more than a standard Yuasa battery.