One should be more than enough.
I use these small sealed batteries. I buy them as
emergency lighting but I suspect they are the
same as a trail camera battery. I don’t know
how long one will run on one of these but
I’m likely to go out 3 or 4 times a day which
would be a couples hours of running and
I never killed one. But like my gas can I always
bring a spare.
I by this brand on eBay. They cost a bit more
than some others they offer but these last years
longer.
It doesn’t take a lot to make them run.
https://youtu.be/PotK2rSrJC0?si=wZAN4AvlLSy6b34C
Tubs
.
A "Boathouse Repair" is one thats done without having tools or the skills to do it properly.