As stated the battery is the weakness of electric, the lakes near my home are electric only. They are not large, but are spread out so to fish the entire lake lots of power is necessary or extreme travel time. Motors are advertised with lots of horse power, the required batteries and their weight diminish their usefulness. Many of the tournament boats have so many batteries on board they are riding very low in the water, one told me it's a never ending battle. More speed for a longer time requires more battery, more battery more weight slowing the boat and increasing the power needed. Solution more batteries, around and around.
I have taken the plunge with a 48 volt system hoping that I can get more fishing time and less travel time. The lithium battery has helped but it still has many limitations. The moral of my rant is electric only is not desirable.