Plugged In Or Not? Alternatives

[Oswego John]

Philip and Sharon:

We keep Mariah at a dock with the AC cord plugged in and a True Charge 20, 3 stage charger on float when we are not around. Being in the fresh waters of Lake Superior, I don't believe (and please, someone correct me if I am wrong) that galvanic corrosion is as big a problem as our sea water brethren experience. We

John Danicic
CD 36 - Mariah - #124
Lake Superior

John,

It is my belief that you are correct in your thoughts in regard to galvanic corrosion and electrolysis in fresh and salt water.

Years ago, many years ago, I used an experiment to illustrate the current carrying ability of water. I mentioned this previously and it's in the archives somewhere.

I would screw a light bulb into a common pigtail type socket. The socket's white ground would be attached to a male plug. From the plug's hot side, I would attach another wire whose other end would be skinned bare of insulation and immersed in a glass of tap water. A third wire would be skinned and also immersed in the same glass of water. The third wire's other end would be attached to the hot side of the lamp socket.

When the plug was put into a 110V wall outlet, nothing would happen. The electrolyte (water) had too much resistance to conduct enough amperage to light the lamp. As regular salt found in a salt shaker was sprinkled into the water, the conductivity would increase and the lamp would begin to glow. The more salt that was added, the brighter the lamp would become. When enough salt was added and the water agitated, the lamp would attain full brightness.

Pure, clean water has high electrical resistance which relates to little conductivity. As the water becomes more contaminated, the resistance decreases. You don't hear much about it, but for this very reason it is recommended that only distilled water be used in your batteries to prevent internal electrical leakage and premature failure. Before anyone gets defensive, I would guess that maybe 1% of us use distilled water and 99% of us use tap water to top off our cells and we still get long life for our batteries.

Mecca for most electricity is earth ground. It will seek out the path of least resistance to get there. This also applies to lightning. It will find ground easier in salt water than in sweet water.

As far as galvanic corrosion goes, I feel that salt water provides a better electrolyte than sweet between dissimilar metals and therefore enhances the corrosive effect.

O J

[Parfait's Provider]

Gee OJ, it sure is nice to know I am in still another fringe group.

[Oswego John]

Hi Ken,

After reading your post, I began thinking of your propensity to "Dare To Be Different." It doesn't bother me one bit (I was going to say iota, but I didn't want to sound like hi-tone Ruby) if you don't want to yank the plug of the charger. As a matter of fact, I sort of like expensive paperweights made of dezincified props.

BTW, Have you ever given thought to using a wooden prop? It should be made of treated lumber for the long haul. It could probably be coated with a concoction made of Morey's Red grease, Marvel Mystery Oil and wood flour mixed with pulverized moth balls to deter marine growth.

Fringe group, schminge group? Nah, not you Ken. You're one of the good guys.

Well, - - - maybe you might get profiled a bit as one of those diehards who simply refuse to pull the charger plug for the simple fact of "Daring To Be Different."

Don't pay any attention to those surveyors. What do they know?

Best regards,
O J
yank, yank

[Parfait's Provider]

OJ, that hurts! Stop pulling my chain like that!

[Bob Ohler]

John Vigor,
When you start on one battery only, say battery #2, when the engine starts, do both batteries charge when the engine is running but with the battery switch still in the #2 posotion? Bob O.

[John Vigor]

Hi Bob:

I normally use both batteries for starting, but if I should use only one, I would switch to "Both" as soon as possible. My switch allows me to do that while the engine is running, without blowing any diodes .

If you are switched to "1" or "2" the charge goes only to that battery. If you switch to "Both," the charge goes to both batteries, not in equal amounts but according to their individual needs. Whichever battery is most run down will automatically receive the greater charge.

When the engine is stopped, and not charging the batteries, however, I switch over to one battery only. If you leave the switch on "Both," the batteries are in contact with each other. The battery with the greater charge will try to top up the one with the lesser charge. Then, when they are about equal, the flow will be reversed and the now full battery will try to top up the one that just gave up its voltage. This goes on and on, back and forth, in a lose-lose situation until they manage to run each other right down. The the total battery bank goes bust.

If you keep them isolated from each other by switching to either "1" or "2," they can't run each other down.

The only reason I use two batteries for starting is that I happen to have two deep-cycle batteries. This type of battery releases amps more slowly than a dedicated starter battery, which is designed to release a great surge of power for a short period. Thus, I use two slower surges which, when combined, tend to keep the power-hungry starter motor just as happy.

I guess the logical thing to do, if you have two batteries, is to have one dedicated starter battery and one deep-cycle battery. I don't remember now how I come to have two deep-cycle batteries. Some basic mismanagement, no doubt, but I don't sweat the small stuff. Somehow I muddle along quite nicely with what I have.

Cheers,

John Vigor

[Mark Yashinsky]

have you upgraded you charging system and how is it wired to the batteries?

[John Vigor]

No Mark, I haven't upgraded the charging system. But I have a Westerbeke 13, which has a 50-amp alternator.

John Vigor

[Bob Ohler]

John, Is it safe to change the position of the battery selector switch from both "1" or "2" to "both" while the engine is running? From your previous post on this subject, I assume this is common practice for you. Now, I also know that switching the switch to "off" while the engine is running is harmful to the alternator, right?
Thanks,
Bob O.

[Bill Sonntag]

All:

This discussion is a good one to raise a point about sailing - simplicity. I read all the trade press about world voyagers and their ability to manage complex systems. I know that when I take on some blue water passage making I will tick up my level of expertise about the really extraordinary safety, weather information, telecommunications, navigation, water supply and other systems available today. Ocean Navigator has keep me at least informed, not expert.

So a question about a power cord - my Cape Dory 31 simply does not need to be plugged in when I'm not aboard. I value the dockside ac system for many reasons, hot water, dry heat when needed, air conditioning during the hottest parts of the Chesapeake summer, but I know how to chill the icebox so it holds, keep the batteries charged with the alternator, manage the dc load on the simple battery set up.

I'm a weekend and occasional longer cruise sailor and simple is better. The world and my place in it is complex, sailing is a respite. Besides, systems always break, I want to sail not fix'em.

Simple answer, don't install systems that require shore power when you are not aboard. All the good reasons given in response here are enough.

PS Care to check out a superb historic yacht restoration - see www.cyrg.org for the story of the 1888 Lawley yacht ELF's restoration. We splash in 56 days, run the bare hull to Philadelphia with my CD 31 as escort - install the 1888 rig that has been completed and awaits us at the Independence Seaport Museum. Then its back to the Chesapeake for a celebration and on to New England for as many antique and classic yacht regattas as we can make. Mid Atlantic and Northeast sailors, look for ELF this summer she will be unlike anything you have every seen!

Bill Sonntag
SURPRISE
CD 31
Georgetown, Maryland

[Neil Gordon]

John, Is it safe to change the position of the battery selector switch from both "1" or "2" to "both" while the engine is running?

Some switches are designed to be safe. Otherwise, NO!!! There's a dead spot between 1/2 and both, which is the same as turning the switch to off.

[John Vigor]

John, Is it safe to change the position of the battery selector switch from both "1" or "2" to "both" while the engine is running? From your previous post on this subject, I assume this is common practice for you. Now, I also know that switching the switch to "off" while the engine is running is harmful to the alternator, right?
Thanks,
Bob O.

Bob, some switches are idiot-proof and I presume that by good luck mine falls into this category. In other words, it makes the new contact before it breaks the old one. There is no dead spot. The only warning I've ever read in connection with my battery switch is that you shouldn't turn it to "Off" while the engine is running.

Cheers,

John Vigor

[Stan W.]

It is my understanding that "make-before-break" switches have been the industry standard for decades. I don't think you could buy an Off-1-Both-2 switch that was not make-before-break even if you wanted to.

[M. R. Bober]

Hi Ken,

...
BTW, Have you ever given thought to using a wooden prop? It should be made of treated lumber for the long haul. It could probably be coated with a concoction made of Morey's Red grease, Marvel Mystery Oil and wood flour mixed with pulverized moth balls to deter marine growth...

Don't pay any attention to those surveyors. What do they know?

Best regards,
O J
yank, yank

Would a wooden prop provide less drag--compared to one that is locked--if left to freewheel while underway??

Mitchell Bober
Sunny Annapolis (where we have seen the future and varnished it), MD

[Dean Abramson]

Shame on you, Mitchell.