The very first thing I would do is disconnect and charge battery, then take and have load tested. Sounds like from here that your not charging and battery was dying. Losing voltage to ignition maybe just charging enough to run the electronics on ignition. If battery turns out to be good, get a meter and check battery voltage then crank motor and check to see if it is charging. Should see a voltage increase when motor is running from about 12.5 or so to about 13.7. Doesn’t take much voltage to run pumps or trim. Takes a lot to turn motor over.