Batteries - Current & Lightning - Oh My

[ebb]

Two agm group 27 batteries could fit in the bilge under the sole forward of the companionway, I do believe. It would put that weight lower (actually over the ballast) and more toward the center.
What are the pros and cons of battery placement? The terminals would be just under the sole. Is this begging for trouble? There's never going to be more than a cup of coffee in the sump.

[Bill]

Probably an ok location as long as you are not taking on water for some unplanned reason:p If the new gel batteries are sealed and you can somehow waterproof all the connections . . .

[Theis]

I have gone out of my way to keep the battery and all connections as high as possible. If something goes wrong, the last thing you want is for the electrical to fail (no electrical pump, no radio, no lights, no nothing). My battery is located on the port side on the aft side of the aft cockpit bulkhead, as high as I could get it. The shelves would almost have to be afloat before it the electrical system was done in. Access is through the port lassarette. Although it is aft of the center of gravity where you wer thinking, it does not have the leverage that it would if located in the motor lassarette.

[ebb]

ok, Thanks. Imagine somebody has a patent on a simple marketable solution like, say, a 3" plastic cup with a waterproof cable tail that is secured to the battery case terminal areas with a hose clamp. Maybe the battery is vented up the same exit with the cable in a companion tube. I could have retired to florida with an idea like that.
I like Theis' radical battery arrangement because it IS so protected. It's a good idea to have the starter bat close to the OB, right? Maybe the juice for the conviences can be mounted lower and near panels.
(I'm putting in a propane locker for a portside stove on the left in back of the cockpit, why not a starter bat locker on the right?)

[Theis]

Another thought. On the side of the bulkhead opposite the battery, in the cabin near the shelf, I installed a high amp main cutoff switch. When I leave the boat, and that is switched off, I know the battery is isolated and wont be dead when I return the following week. A word of caution: The cutoff does not cut off the line to the outboard. You may burn out your outboard generator if the electrical is not connected to a battery (the battery acts as a capacitor) when the OB is run. The line from the outboard to the battery must always be connected (at least with the Yamaha, and probably with most other brands as well, I suspect).

I thought I would be having an electrical starter for the OB and ran #6 wires from the battery to the motor well. Not necessary now that I don't have an electrical starter, but they are in place if I ever need them.

[ebb]

A capacitor is some sort of an electrically charged momentary switch? Why is a storage battery acting like that? The charging current goes one way in, then shuts off at capacity, and the charge still continues on a dead loop?
I.m so dumb on electrics it's a joke. But not to me. It took me through lunch to get the failsafe main switch setup you have. but in no way can I visualiuze it.

Can you, Mr Theis, be persuaded to professionally ($$) design a basic electric system for 338? A system that could be customized or added on to later? A kind of guidance system for the electrically challanged in 12v dc?:o

[ebb]

well hell I just stumbled across a huge resource on the glissando page. When it's time to get wired I'll just plunge in - 381 lighting the way!! A thousand thanks!:cool: :cool:

[Theis]

You're really stretching my memory from engineering school with your question about batteries and capacitors. Batteries are considered huge capacitors, and in power generation and inverters more commonly known as "accumulators". They are used to hold a fixed voltage and prevent voltage spikes. Just like a capacitor, they store a charge, and then release it on demand, or when the voltage changes to negative. When you try to start a motor and connect the positive terminal to the negative terminal (ground), through a starter as resistance, it discharges. When you charge a battery, it stores the positive AC segment above its ambient level (above 12 Volts positive), and then, when below 12 volts positive, diodes prevent the reverse flow of current (discharge back into the generator). The capacitor concept regarding batteries is true not only for big wet cells, but for the little alkaline batteries as well.

Over the weekend, I will try to draw what I have done to the Atiel electrical system. The reason I redid the electrical system, incidentally, is that I have had two different marine surveyors look at the boat on two separate occasions (going back a few decades) and on both occasions they faulted the electrical system. Since those surveys, the standards for boating electrical systems have been tightened up. If I get it done, I will start a new thread so the design of the electrical system can be discussed as a separate issue.

[ebb]

I for one am really interested in what you have done to illuminate yer Ariel. I'm still somewhat incapacitorated and impatient to have your dark science graphically revealed.

[noeta-112]

I'm with you, Ebb. The sailboat electric doesn't make a lot of sense to me either. No ground plate on Noeta and I s'pose if the lightning strikes it'll blow the thru hulls through the hull.

From all I can gather you gotta have (if desired) 2 separate systems. One purely for electrical generation and consumption and if desired one system for lightning strike protection....(or attraction as some might argue..);p

[Theis]

I grappled with that one, and my research has concluded that both lightning ground and boat are connected at a single point, closest to where ground plate. I think, if you check, you will find a wire connected to your water inlet valve in the forward cabin on the starboard side. I believe that was company issue. That wire is the ground connection for lightning. I have never heard of a Alberg boat being hit (although it may have happened), but I am familiar with others - and many others are not water grounded (they are made in California where they don't have lightning). Incidentally, there is a good read on Sailnet this week about this very subject. I'll try to put the URL on this site.

[ebb]

So why wouldn't a lightening strike blow a thruhull out the bottom of the boat?
Like it looked like it was all wired together on 338 until I tore it apart. Plates & thruhulls - but somehow they missed grounding the stem fitting and the rudderpost. And the backstay plate.

Find the Kittiwake 23 site and you'll read of a guy's experience on his Alberg that evidently melted his frigging whole system and carbonized all his toys. Really. It's a great homey site and fun to visit.

[Theis]

First off, based on what I have read, there is no such thing as absolute protection against a lightning strike - other than, as I have been taught, if you are within the perimeter of the stays, you personally are protected because the stays form a "Faraday cage".

You are on point that the wire to the inlet valve is too small, and the inlet valve itself is too small to take a major hit - but it is effective in all but the worst situations. What some people do is to hang battery cables from the stays when entering a lightning storm. What the experts say you need is a copper plate on the bottom bonded to the stays and the electrical system. I have a 6"X18" plate which is about half the size it is supposed to be for fresh water (but sized right for salt water). I am the only person I know that has gone to this extreme. Others, however, have the Guest sintered bronze shoes that are not advertised as being for lightning ground, but appear to be effective. I also carry one of those Forespar metal brushes on my masthead.

The book about lightning that I considered to be the best I have yet come across to take the "I don't know how it works but maybe ..." out of the witchcraft concept is

Lightning and Boats, a Manual of Safety and Prevention, by Michael V. Huck, Jr. It is published by Seaworthy Productions, 17125C West Bluemound Rd., Suite 200, Brookfield, Wisconsin, 53008. The ISBN is 0-0639566-0-4

The sailnet URL that discusses this topic, (with a forthcoming issue specifically about lightning) is http://www.sailnet.com/view.cfm?page=9067

Do you have the URL for the Kittiwake story?

[ebb]

Thanks for all this good thoughtful feedback.
The grounding plate is, what, a thick piece of copper slapped onto the side of the hull underwater like sacrificial zinc on a fishing boat? No, so it's faired in - and the cable how does it go to the shroud plate? A hole in the side? And something that size disapates the lightening strike without the possibility of blasting your side out? What's better: battery cables, grounding plate, or both? Intense prayer.

Kittiwake 23 site: www.crosstel.net/~jlfrnkln/
Scroll down on >History< to Owners Feedback, 1st entry.

[Theis]

The Kittiwake sotry is interesting, and I believe he is correct about the cause of the problem. I have no confidence that he has corrected the problem now however.

I am assuming his mast is aluminum. The stainless steel bolt he is using will galvonically corrode when connected to aluminum. That WILL happen - and again there will be no electical connection. That is why when you put stainless steel screws into your aluminum mast, alwsys coat the screws with anti-corrosion cream (which is not a conductor) but prevents the threads from corroding and the screws from pulling out.

Keep in mind that the lightning does not "strike" the mast in the colloguial sense. What happens is that the mast head, if not adequately grounded, builds up a positive charge - and that positive charge can be quite high in electrical potential (that is why people's hair stands on end before they are struck) The way to dissipate and prevent that charge build-up is through the very low resistance path to water ground. If there is even a small resistance path, then the charge will build up, the point of resistance will heat up further increasing the resistance and the boat will attract a lightning strike. If there is a low resistance path, a positive charge can not build up on the masthead.

This positive charge build up on the mast head attracts the negative charge on the bottom of the cloud. The positive "streamer" actually goes up towards the cloud to meed the negatively charged streamer coming down from the bottom of the cloud. When they meet, BANG!

The fact that the bolt blew out is indicative that there was a high resistance path at the connection with the mast. Otherwise there would have not been heat generated at that point and the bolt would not have blown out. Once the main path was broken. The lightning went whereever it decided to go and blew out everything.

In my Ariel originally, all the shrouds had a 12 ga. wire connecting them together (on both sides, but not connecting the port to the starboard side). I have now increased this to a 6 ga. Because the stainless shrouds are individually lousy conductors compared to the aluminum mast, it is worthwhile having them all shrouds connected together so there are six parallel paths (grounding the mast base with an aluminum bolt is evern better. Originally here was then a 12 ga. cable going from one of the starboard shrouds to the water intake. I connected a 6 ga. wire from the port side shroud to the bow pulpit, and a similar 6 ga. from the bow pulpit to the starboard side, so the base of both sets of stays are connected both at the masthead (by a stainless steel bolt and plate - so galvonic corrosion is not an issue at the masthead. From the base of the shroud connection, the #6 cable goes to a 3/4" copper bolt connected to the copper plate. The bolt has to be large - much bigger than the wire size. Current only flows on the outside of a conductor. The wire is multi-stranded so it can be smaller in diameter than the bolt if the wire has multiple strands. The bolt, on the other hand, is like a single strand. And remember, a stainless steel bolt is a lousy conductor. I would suggest you only use copper or bronze (or aluminum in the worst case) for your through hull bolt, and make it as large as is reasonably possible.

The entire plate/bolt/whatever combination I bought at West last year (about $38 as I recall) and it came with complete instructions. Look in their catalog under lightning or contact West Marine (I don't have a catalog here or I would do it for you).

Many people just use battery cables laying over the side but connected to a shroud (assuming all shrouds are connected to one another internally as I commented), and I won't fault it in addition to the grounding plate as a good idea just for piece of mind. That is better than having lightning going through a through hull fitting if the main system fails. The problem with the cables, is that the area of surface contact with the water is is not considered sufficiently large.

The copper plate, or lightning shoe, should not be faired. It is the edges (and the corners) that prinicipally dissipate the electric charge, not the smooth surface. If you fair the plate, you will lose the edges. And NEVER paint the copper plate or your shoe. All metal through hulls should be tied (bonded) to that shoe so that there can not be any voltage buildup between various through hulls (i.e. lightning can not jump from one to another as happened in the Kittiwake).

Another safety precaution is to annually take a volt meter an make sure there is no resistance between the grounding plate and the mast. If Kittiwake had done that beforehand, my bet is that he would have realized his mast was not grounded.

[ebb]

Take a suitable length of #6 stranded marine wire, winde one end once around a bolt of the aftlower shroud plate and tighten the nut? Proceed similarly to the uppershroud plate on the compression bulkhead with the same wire, one turn round, tighten nut, and then to the forward shroud plate? Take the same wire to a bolt of the forward pulpit socket fitting, Connect. Take the same wire to the other forward pulpit fitting?

Do the same with the other side up to the other fpf. Then take both wires over to the grounding nut(s.) Most Ariels still have 4 metal thruhulls (mine are history.) You connect these singley or in series and take tese wires to the grounding plate stud?

Is the mast also wired to the grounding plate with a wire from the mast, thru the deck, down the bulkhead, etc?

Defender has 4 Guest Dynaplate grounding plates listed (pg210, 2002.) In inches: 6 X 2 (50.49) - 8 X 2 1/2(82.49) - 12 X 3(131.79) - 18 X 6(274.79). Cryptically they "protect" 12 - 20 - 40 - 100 sq.ft. In the miniature illustration they have 2 holes and are vaguely hydrodynamic. These any good? Where did you place the plate on the hull? Paste it on with 5200? Guest and Whale products have a largely lukewarm reaction on the web. Hope I get a passing grade!:rolleyes:

[ebb]

What is the difference between lightening strike protection to a grounding plate and bonding all your bronze spincters and chainplates together? And going to an external grounding plate? I'm confused. And I think I remember a controversy around bonding - whether it's necessary or if it doesn't promote galvonic action.
When the big one hits, or when your mast rises up for that good shot, you want a direct route to the water, no? Do we want it following #6s around inside? Let's weld dynoplates to the aligator clips of a battery cable and fasten the other ends to the upper shrouds.
How do you keep the electric system ground separate from the lightening protection system? This stuff hurts my head

[Theis]

The dynaplates are what most people use for grounding. Guest, however, disclaims their use for lightning protection and the organization that figures these things out does not endorse the Dynaplate. That does not mean they don't work. Rather it means that they don't have the benefit of the equivalent of Coast Guard Approval. Frankly, I don't understand why they are not approved, unless they figure that the porous bronze. Guest may just be trying to avoid the insurance liability.

I would assume that with the Dynaplate you get a good set of instructions that will explain these things a lot better than I can. After all who am I but a dumb Swede that doesn't know better than to not go out in a lightning storm.

I do notice that the grounding plate I bought from West is not listed any more (I bought mine last year), so you might want to contact them and ask the question where you can get them and why they are discontinued.

The plate is mounted with 5200 and should be placed as low in the water as possible. Mine is mounted on the bottom directly under the starboard hanging locker.

As for the connections to the stays, you are correct to a point. You only need to connect one shroud to the ground point. Don't worry about the aft or bow stay. Connect the wire to one of the bolts that goes through the chain plates, but in my case, I wired the three chainplates on each side together. Make sure there is no paint on the chainplate of the bolt where the wire is connected. The contact must be good metal to metal. For peace of mind, you can wire both the port and starboard chainplate to the bonding point. I did that through the bow pulpit as I explained.

Although the wire could be twisted aroung the bolt as you suggest, I would use an Anchor crimp ring connectors. You want to be right on that connection - there is no room for error - or you will have the Kittiwake type problem. I am not pushing West, but they have been helpful to me. I had them mount the crimp connectors on to the 6 ga wire (so that I wouldn't have to buy the tool).

As for the current going inside the boat, in my opinion, that doesn't make any difference - as long as there is a near zero resistance path. If not, the lightning strike will go whereever it wants.

Make sure the bow pulpit is grounded also. That extends outside the stays and, if not grounded could give someone a jolt.

As for the single point grounding, if the grounding plate is good, and your electronics are connected to the grounding plate, the lightning will not pass through the electronics. The battery ground and water ground will always be the same, lightning strike or no.

Now, what I don't know about is the antenna. There is a lightning suppressor on the Shakespeare antenna that causes the lightning to jump to the masthead fitting and not pass through the antenna to the VHF radio. That should solve the problem there, but if that doesn't work, there goes your onboard VHF - which is the reason you should also carry a portable VHF - after all it is only money.

Hope this helps.

[ebb]

Thanks Theis, may Thor keep his thunderbolts to histhelf next time yer out in yer little thip!

Couple things: You used the smallest grounding plate. right?

The heel of the mast is also grounded?

The crimp rings certainly are the best way to connect to the shroud plate bolts but how did you get them to crimp in exactly the right place? Have them come to your boat?

My guess is also that the wire runs should be as strate as possible without loops and ins and outs?

Be awhile befor I do this, but I will. Don't know if weather is better reported but it seems like it is getting crazier & crazier. Grounding for lightening protection is the way to go

[Theis]

Heel of Mast: The answer is that there is little reason to ground the heel, and I haven't seen that done when the shrouds are grounded. However, I have considered doing it to be as cautious as possible because the aluminum mast is so much better a conductor than the stainless. If the stays were not tied together electrically creatting effectively multiple parallel circuits (the total resistance would be the resistance of one stay divided by the number of stays tied together), I probably would ground the mast base. However, as your Kittiwake story points out, the issue then becomes how do you bond the foot of the mast to the wire? The foot is often wet fostering corrosion, and even if you use an aluminum bolt, aluminum corrodes as well. I don't know the answer, but I have not bothered grounding the foot and don't think it is really necessary. I would classify it as overkill.

Keep in mind that with electricity, generally, the physical path is not relevant. The relevant issue is the low resistance path. In other words, for example, if the port side shrouds are not grounded, it doesn't make any difference because the low resistance path would be the grounded starboard side shrouds. The same with the back stay. However, if the starboard side is not adequately grounded , then there is a totally different story.

What I am considering doing next year as a result of this dialog is to run a short length of 6 ga. wire from the masthead lightning rod to the masthead plate that holds the stays. Right now, that rod is connected to the cast aluminum masthead fitting, which then is connected to the aluminum mast, which is then connected to the stainless plate. There is plenty of surface area with those connections, so it is reasonable to assume there is no problem with resistance, but then on the other hand, how can you be sure. I don't know at this time. Perhaps in the fall when I take the mast down, I will do a resistance check.

By the way, in the way of filling you in on a detail or two, the problem with the least bit of resistance is this. Let us assume that the resistance in a connection is only 0.01 ohms. - which may even be hard to measure with a cheap meter. If you have a million amps going through that weak spot, the voltage across that connection is 10,000 volts. The heat produced (which is proportional to the square of the current) will cause the resistance to increase until there is arcing - slash a flash. If the voltage becomes high enough for the current to jump from the stay directly to the water, that is what it will do rather than going through the weak spot. With the bonding kit, there was included a copper based high conductivity paste that was put all over the bolts and nuts to be sure there was conductivity. You might also look into buying some of this stuff. I would suggest West or Radio Shack. If you can't find it, I will see if my bottle lists the manufacturer

Keep in mind that the purpose of a lightning rod (i.e. the mast) is to prevent a lightning hit, not to discharge it after it has hit. To get rid of the positive charge accumulation so that lightning is not attracted, the current flow is less than with lightning, but over a longer duration. I point this out because we can never achieve perfection in this life, and we are aming to maintain this life with this exercise, but the closer you can come to the ideal connection, the more comfortable you should be.

I got the biggest grounding plate that was commercially available and that I could afford. Almost anything is better than the through hull that was on the original Ariel. But then even with that as company issue, I have never heard of an Ariel being hit by lightning and that is over a period of forty years. Maybe someone has a tale to tell.

How to get the wires the right length. I started cutting them to the right length and then taking them to West. That go old so I finally broke down and bought the $30 fixture - which, unfortunately fell into the big pond last fall.

Straight runs. Yes. all runs should be as straight as possible, and where there is a bend, the radius should be as large as possible. There is one bend, for example, in my Ariel in the line from the chainplate to the bonding point in the hull, and that probably has a 6" to 1 ft radius. The bend is inside the starboard side locker.

As for through hulls, I only have two metal through hulls in the forward cabin for the toilet. The cockpit through hulls are fiberglass, which doesn't count because they don't conduct.