Final note: The best reason to go through the hoops of re-doing one's power system is that it forces you to understand what all the damn wires are there for.
Alternator
- Thread starter Navman
- Start date
Pete the Cat
Sustaining Member
Yes, I guess we all need to go through that, at least mentally. But the trip really soured me on all the electrical sales folks over selling all the complexity and capacity to bedazzled yacht owners who may not be starting with an idea of what they actually need and will use. Understanding acceptance rate of batteries and the charge rate of smart regulators is the key. But having gone through all that, I now realize that a couple of old 100ah flooded batteries, the old Motorola 50amp alternator and a 100w solar panel and regulator probably meets the needs of most folks if not doing air conditioning or induction ranges.
bsangs
E35-3 - New Jersey
Now you're talking my language. Though it's a 200w solar panel, and I bring aboard a couple large capacity rechargeable Bluetti batteries for anything that requires AC on our trips.
peaman
Sustaining Member
That exactly describes my system after doing a significant rework 2 years ago. I also have dedicated start and house banks. All charging goes to the house bank and an ACR tops up the start bank. I replaced the common Off-1-Both-2 switch with a dual switch to keep the two banks separate. A Victron battery monitor keeps me informed on system status.
Right, and when cruising no need to recharge anywhere near 100 percent. Discharge to 50 percent, charge back to 80 percent (avoiding the very slow charge rate when topping off a battery--the nonlinear factor). A bigger alternator with smart regulator can do that in somewhere around an hour of engine time. Which if you motor a little every cruising day, happens "automatically."
Add up the typical drain per day and see how close it is to 30 amps. Most appliances don't have to be on all the time, including the refrigerator.
Add up the typical drain per day and see how close it is to 30 amps. Most appliances don't have to be on all the time, including the refrigerator.
Navman
Member III
I found an alternator shop which is rebuilding my old alternator so as to give it 70+ amps. I believe that will be enough. I am installing 2, 200.watt solar panels in the spring. I think the combination will supply my needs. I do a lot of coastal cruising to New England ever other year and 2 week vacations on the Chessie on the off years. Iand am always at anchor at night and have never stayed at a marina when sailing,so I don’t want to worry about ample power. I think this setup will meet my criteria. I do carry the Honda generator as a backup if needed.
Navman
Member III
I am picking up the rebuilt alternator tomorrow and going out for 5 days and nights, so I will be able to check it out. I will be picking up a ball in Annapolis on Thursday as my friend has never been there. Then over to San Domingo Creek and St. Michael’s . Might even get back to Oxford. All nice spots and usually quiet this time of year
Nice! Fall, before we get snow and ice... is a great time to cruise the NW. Uncrowded docks and anchorages.
Joliba
1988 E38-200 Contributing Member
We also have 4 AGM batteries. We bought the boat 16 years ago. The PO had installed a high output alternator a few years earlier. It is an AmpTech alternator. (I can’t recall if it is rated at 100 or 105 amps). We have had no problem with it using an external voltage regulator. I believe it is a good alternative to BalMar and possibly less expensive.
Mike