I have three of
these each (more similar
options out there I'm sure) hardwired semi permanently config that live (each basically sit on top of each batt) with my 3 wet batts...........I then have them all plugged into a triple 120VAC outlet that goes to one 120VAC cord that just lays in the engine well. When needed, I just un-coil that cord, throw it out the back and go plug it into the house.....done!
All three have their own cheap but decent independent maintainers. Could spend $400 on a high rate triple output, but don't require rapid charge, just maintain or overnight'ish recharging if one doesn't get back up far enough by the motor's alt.......Sounds like that's what you want at your moorage.
Usually used mostly in Winter during deep sleep/sub zero temp's is where I will plug it in maybe a few days in a row like every other month just to make sure they all top off, if it 's like 0'ish degrees F for like weeks in a row, I might just leave it plugged in .........Could leave it 24/7, but that's not really necessary for my needs.
