My sailboat has 2 4D flooded lead acid batteries on an 1-2-both switch without an additional dedicated starting battery. I think this effectively makes each battery a separate “bank” in the vocabulary of this forum. We normally use the #1 battery on odd days and #2 on even days, always charging both with the 100 amp engine driven alternator when under power and occasionally when at shore power. Our shore power charger has isolated outputs to charge multiple banks. We primarily weekend on the boat. During the week it is on a mooring without shore power. I want to add 2 x 50W solar panels on the dodger to ensure batteries are well charged when I arrive for the weekend. For occasional 1-2 week summer cruises, I plan to add temporarily mounted 2 x 100w panels to try to minimize or eliminate the need to run the diesel or portable generator to charge while we sit an anchor for multiple days running the fridge And all other comforts of home. I plan to run all the panels in parallel since there is always a shadow risk on a sailboat. We always switch the battery switch off when leaving the boat. I bought a smart Solar mppt 100/30, but now realize that since the batteries are set up as two separate banks, simply hooking up the single output to one of the batteries will not work as intended and hooking up to both batteries effectively combines the batteries into one bank where one battery will charge the other. Any ideas? The simpler the better, please. Thanks from a novice.
