I have a 1991 200hp Yamaha 2 stroke. I have 3 batteries in my boat with an isolating switch. Battery No 1 is single a marine battery. Battery No 2 is two marine batteries connected in parallel. My question is, will the outboard charging system be able to charge all three batteries at once with the switch on "both". What I have been doing is alternating between 1 & 2, but I would like to charge all three at the one time.