I just got a 20ah Amped battery to run my livescope. My boat is only 14ft so weight is a huge factor. I park my boat outside so I bring my electronics and battery inside when not in use. My Amp battery weighs 4lbs while a deep cycle battery weighs 45lbs. The lithium battery cost around $35 more than the deep cycle which makes cost a non-factor for me. Buy chance a buddy of mines sold me a 18ah Amped battery for $50. It has only been charged 3 times before he sold his kayak. Due to cost I doubt I buy a big lithium battery to run my trolling motor but they are the cats meow to run your electronics.