When I’m at the lake, weather permitting, I’ll be out 2 to 4 hrs. a day. Sometimes longer. 2 years ago I brought a 1928 Speedster. Wide open is around 4000 RPM. Ruddertwins don’t spin that fast because the gas tank restricts the movement of the timer. I had one, 5 year old Power Sonic battery like the one you posted a picture of, and a new one. I decided to see how long the old one would last as I had the new one as back up. The old one lasted 6 days. At just 2 hours a day that would have been 12 hours running on a 5 year old, 4.5 amp, PS battery. When the black ones pictured in my box were 3 years old, after an hour running, the motor would started missing. PS batteries cost more but are well worth it. This is my experience.
A "Boathouse Repair" is one thats done without having tools or the skills to do it properly.