geezer wrote:We are hooked to shore power while at *dock so 20 amp would work most of the time, but planning a trip to Desolation Sound for a few weeks next summer and will be recharging using the generator when we're not running. *Think I'll split the difference and get the three stage 40 amp- sounds like the best of both worlds.
Your world of reality as described above does not always match the world of theory, a lot of which one tends to get on forums like this.
As built, our boat had a very simple electrical system and still does.* In fact it is still totally stock except for the recent substitution of six 6vdc golf cart batteries for the stock two 8D batteries (three golf cart batteries fit very nicely in a single 8D battery box).* We also replaced the original "American Marine" adjustable but single-stage battery charger (don't know who actually made it) with a Heart Freedom 25 inverter/three-stage charger a year after we bought the boat.
Due, perhaps, to our many years of experience with British narrowboats, we are pretty conservative with DC power when the boat is moored or anchored.* Reading lights, the AC/DC refrigerator, the occasional use of a Bose SoundDock, and the occasional use of a laptop if I write on board comprise our DC requirements.* Our stove/oven is propane.
We have an inefficient (by today's standards) Norcold refrigerator that had been installed new by the previous owner the year before we bought the boat so it's now something over 13 years old.
Our boat is equipped with a Jurassic Period generator, an Onan MDJE 7.5 kw unit.
We took the boat to Desolation Sound for three weeks a few years ago, and have been taking two-week trips into the Gulf Islands periodically since then.* So far--- other than a problem with the Norcold which seems to have straightened itself out for some mysterious reason--- we have not had any problems with DC electrical system or the components connected to it.
The engines (FL120s) have their stock Motorola alternators which I believe are 45 amp or thereabouts units.* We had them overhauled a number of years ago but other than that they are the same units (I assume) that have been on the engines since 1973.* On the days we don't move the boat we typically run the generator for an hour sometime during the morning to heat water and throw a charge back into the batteries.
We are not social boaters-- we bought the boat to get away from people, not join them--- so we avoid marinas whenever possible unless we have guests who would like to see what some of the unique harbor towns in BC have to offer.* This means we are not on ground power all that much during a cruise.* And even in a marina we often will not bother to hook up the ground power cable if we're only going to be there for a night or two.
So my prediction is that, if your batteries are in good shape, you will have no problems whatsoever with your current electrical setup on a three-week cruise to Desolation.* Particularly since you say you have a generator you can use in the event you decide to hang out in a particular anchorage for a few days.
Installing a three-stage smart charger is a good investment regardless of how you use the boat as it makes life a lot better for your batteries and reduces the risk of overcharging, undercharging, boiling them out, etc.
Also, we have so far been very happy with our decision to change from two 8Ds to six golf cart batteries.* Four of them are wired together into our "house" bank and the remaining two are our "start" bank.* Besides being a hell of a lot easier to physically replace when the day comes, this has effectively doubled the amp hours available for house loads.
All this has been a wordy way of saying that, based on our experience with our boat, the plan of action you outlined above seems to be a very common-sense approach for what you're planning to do.
Regarding propane refrigerators----* Some of the narrowboats we hired in England were equipped with propane refrigerators.* Based on that experience, I believe a propane refrigerator is the best way to go on a boat as far as the refrigeration "experience" is concerned.* Dead silent in operation and extremely effective in getting stuff real cold real fast and keeping it that way regardless of how hot the day is.* The newer narrowboats we've hired have had 12vdc refrigerators and none of them, as well as the Norcold on our GB, have been anywhere near as efficient in terms of getting things cold fast and keeping them cold. If you like milk chilled to 32.25 degrees as I do, how cold a refrigerator keeps stuff is a big deal
Based again on our experience, I do not understand the fear or distrust so many boaters have of propane on a boat.* Sure, it can leak and collect in the bilge and blow you into the next county when the fresh water pump kicks on or an engine starter lights off in the engine room.* But electricity can short out and burn your boat down, too.* If a boat has a well-designed, properly installed propane system using quality components-- and if it's operated with common sense---* it's probably one of the least life-threatening things on the boat.* You're more likely to die falling overboard and having your leg sliced off by a prop than by being blown to smithereens by the boat's built-in propane system unless you just get really dumb with the propane system.
I find it rather amusing when people who have a propane stove or range on their boats talk about how dangerous a propane refrigerator is.* They're basically the same thing when it comes to operation, the need for a properly designed installation, the use of quality components, and common sense in their use.
If a person has an inherent fear of propane on a boat, or if they truly do believe a propane system has a mind of it's own and is always just a knob-turn away from blowing you and your boat to bits, fine, don't buy a boat with a propane system on it.* But if you don't have this inherent distrust of the stuff, a propane refrigerator--- if it's legal to install one--- can be a wonderful thing.
What I don't understand or like are boats the size of ours--- 30-46 feet or so--- with all-electric galleys and their need to run a generator every time the owner wants to make a grilled cheese sandwich.* We've been at docks--- and Carey can certainly attest to this is we've often been at these docks with him---- where boats are running their generators all damn day.* They do this (they tell us) because everything on the boat is electric and all their AC appliances, particularly the big power-drawers like stoves and convection ovens and whatnot--- can only be powered by the generator.
And there seems to be a law of physics or something that says that the more dependent a boat is on generator power, the louder that generator will be.* The people who rarely use their generators seem to have really quiet ones where all you hear is the faint splash of the cooling water.* The folks that have to--- or think they have to-- run their generators from 9am to 9pm always seem to have generators that reverberate around the bay like an idling Cat D10.
