Carquest Gold Deep Cycle Marine for trolling motor are the best I have ever used. First set lasted over 4 years and they were not 100% dead then but noticed some lost performance so better safe than sorry. Put another identical set in last spring and expect them to last easily to 2013 and then some. I say then some because I learned a lot about maintenance of the batteries over the past few years and if the first set will last 4 years with me not properly keeping them in peak performance then no telling how long the new set will last.