Yes, battery tech has a ways to go. But... Some factors:
Weight:
[Electric MM]
Battery=100 lbs (or more for longer range)
Motor/drive shaft=19+62 lbs
Wiring=10 lbs (I'm sure I'm missing something)
Total: 190-ish lbs
[Gasoline MM]
6 gal gas tank (full)=50 lbs
Motor/drive shaft= 54+62 lbs (Predator 301cc engine weight)
Starting battery=10-20 lbs (or more)
Total: 120-180-ish lbs
Temps: That is definitely a huge factor for batteries. But, your starting battery seems to be taking it pretty well, so...
Obviously you wouldn't need the gas tank with many of the air cooled engines, but IDK how far an onboard tank gets the individual hunter. Either way, each gallon is 8 lbs. And that battery weight is for a very large battery. Lighter ones can be had, but you lose range. My biggest concern is the safety aspect. Electrical fires suck and we know what happens to a Tesla when water consumes it. It is obvious to everyone that electric isn't the "end-all-be-all" solution for anything. But, certain applications could benefit or at least be on an equal playing field as an IC engine. The only sound an electric MM would make would be the "prop-chop" of the water. And, if one wanted to drop some weight and have even more range (at the expense of some noise), we could get into the Honda quiet generator/rectifier/electric motor stuff and pretend to be a locomotive engine.
FWIW, this is all just for friendly discussion. I'm not trying to change anyone's mind or opinion.