This battery sounds great. Only 13 pounds? That's a huge difference vs. lugging around a 50-pounder. Where do you recommend buying one? Beyond weight, how do they compare/differ from traditional marine deep cycle batteries?One could pair this with a new K2 lithium battery and fish all day. These cells are full size trolling motor batteries, but weigh only about 13 pounds. Beats paddling, or peddling.