I am getting the single 300hp. You mentioned one of my primary concerns. How long would the batteries last? I really like the spot lock feature for perch fishing but really think trolling for hours would deplete the batteries. Actually a gas kicker would be around the same cost and possibly less. By the time you add the electric motor for 3k, 3 size 31 batteries, circuit breaker, wiring and a mount plate....
I know some people use bags to slow the troll with the primary engine but not sure I want to rack up hours trolling on the primary.