Multiple Battery Grounding

this is electricity 101.....you only have 1 ground ( or negative)

You can common ground all the battery banks.

Those little electrons know where to go.

I figured as much.

I'm going to going to put a wire across the two bars at the top of my circuit breaker panel and pull the meter.

The electricity will just re-circulate!

Thanks!

Please post the video .

The schematic is a roadmap for electrons. Seriously, that is the sole purpose of circuit breakers, fuses, battery selector switches, and on off buttons. Are you going to do it, or have it done?

I will try to do the job myself based on the existing wiring, and all the input I found here and there (like a spec´s booklet from the US Coast guard, etc). It is basically a common sense task. Before energizing the circuit, I will have it checked by a naval electrician.

So far, nobody has told me where the electrons from the different banks return to!

the electron fairy eats them of course

The electrons that are used are transformed into heat....here's an artists concept of this happening....

There are plain ordinary electrons and then there are marine electrons. Since marine electrons also power lights: running (red on the port, green on the starboard, white on the stern), anchor, mast head, perhaps a second and third masthead light, and perhaps many others they are not the dumb ordinary electrons. They also don't need to operate with a long electrical power cord tying them up to the national grid. They basically follow the maritime rule of "Red, Right, Returning". Therefor they go to the red thing on the right when returning to the correct battery.

Good Luck, Old Salt

You and me belong to different worlds!: Here we say "SIR" which can be translated as "leaving" "left" "red". This is just because we use IALA "B"

Just to blow your head off:

Ah, what a relief to know that when I sail across the equator I don't have to remember a different set of navigation rules, just a different paint configuration and shapes of buoys. If it was necessary I could turn the tiller in the wrong direction and either end up on a long journey up the Amazon or on my way to Gibraltar.

Sailors are not known as being the Einstein's of the world because of the sodium chloride in their blood but most of up can look at the sky and "sail by the seat of our pants". Besides that we can sometimes figure a GPS out. But, correct me if I'm wrong, "Red, right (starboard or as was called years ago, larboard), returning (as in the start of the marker buoys at a channel or heading South) is the same as "SIR"-- "leaving" "left" "red"! In shorter words: red to starboard returning is the same as red to port leaving. For a land lubber it is too confusing so they should let the captain do his/her job and don't bother him/her.

I rechecked what I learned at age 10 and it is the same, as per Chapman's Piloting Seamanship and Small Boat Handling.

Ahoy Mate!

Good Luck, Old Salt

Thanks for the information. I knew larboard became starboard prior to the discovery of North America but not from which country. Also, I always though that "Boom" came from the sound it makes as it hits my head when coming about or jibing when I am standing up too much. Either that or the sound you make when it knocks you overboard. I still like my definition better, more humorous.

Good Luck, Old Salt

The other bit is that you don't moor with your "starboard" (steering board) against the dock wall - it'll probably break,. So in port, the port side goes towards the dock (port).

Starboard comes from old English: stéorboard, or steering board...possibly of Dutch origin aforehand.

larboard is from ladd bord, or lead board. The lead board would be the left side of the ship which was being lead from the right side...where the steering board was.

Port came into use due to the similar-sounding terms. The ship was docked on the opposite side of the steering board...put into port...the port-side of the ship.

OK, OK! You are right, or left? Larboard is beyond the gunwales, named after the "gun ridges", so it is beyond my serious concentration of awareness. I don't sail square riggers, mostly Marconi rigs, so it is not on my list for the chandler nor the compass rose. I am usually interested the alignment of the 32 points, not where 16 of them are on the gimbled device. I am more concerned about attaining a bone in the teeth than what it was called before "port".

Make sure you are on a beam reach and not in irons or an unplanned jibe. Keep the parachute filled on a run. Of utmost importance is to tie off the bitter end to a Sampson post. Trim the mainsail, jib, chute and jenni for minimal luff. Lastly, running aground can spoil your day unless you have a centerboard or dagger board.

Ahoy!

Good Luck, Old Salt

Hi! Rules are just the same, but "upside down" Just an easy example: if you sail from the sea into a river you have to show the "red" light (port) of your boat to the green buoys of the channel. Returning to the sea your boat ligths have to coincide with those of the channel: red to red and green to green. Piece of cake! . IALA B was implemented here about 35 years ago or so. At the beginning it was quite frightening causes former "sunken ship" buoys were painted black with a green light on top, while channel buoys were black with a white or red light on top. Overnight channel buoys were painted green and got a green light. Sunken ship buoys became a white fast blinking light..... Still now (despite all the electronics aboard) I get the shivers when approaching a green buoy at night or in bad weather: it´s sort of instinctive....

According to my memory (and the website below), you are completely wrong.....

That appears to be the opposite of your post, is it not?

See:-

Safety_on_the_water_navigation_signs

The Americas belong to the IALA "B" maritime buoy System, while the Europe and most of Asia belong to the IALA "A" If your source is a website from the UK we are both right!

Ahhh! Thanks for that.....

But how quaint that the USA "goes against the stream" of the old world!! Its not a first though!!

I would NEVER find the sea from a river in the USA!!!!

I would end up s**t creek without a paddle!!

stop here first...

Great pic!!

Just checked it, the website is Australian! so, don´t come to America sailing the wrong way!

Australia takes most of its rules from the UK and Europe.....90% (not exact) of my family lives in Australia....

Rules in both IALA systems are the same... but "A and B" are flipped 180º

Understood....

Justo some more info:

from www.iala-aism.org

sorry for the size, but can´t shrink it!

Only a shellback would know this.

Somewhere in the maze, will be a common ground, whether it be the engine block, a ground bus, saltwater in the bilge or the shield on one of your antenna cables. I have seen all of the above, unfortunately many of them were on US Coast Guard small boats. Even the Cutter I served on would have failed an inspection if it were carrying passengers for hire. (My personal favorite was the boat, when you disconnected the VHF radio antenna the port engine stalled.) Without a schematic, and then several hours of messing around it is virtually impossible to tell. Even on hi end yachts, wiring up until the past few years was a mystery. Out of sight, out of mind. If it didn't contribute to the speed or "sexiness" fuhgetaboutit.

Fortunately or not, the marine industry seems to going the way of automobiles. When you push a button to drop the anchor, you are actually sending a data burst to a uprocessor to close a relay.

There are two ways to solve this dilemma, you can sail it up here to Isla del Encanta, or fly me down there.

The ABYC (American Boat and Yacht Council) offers certification course(s). It is quite good, but expensive. I have found that if you use quality marine rated parts, used within their specifications and high quality tools, you will achieve the desired results. (While it is possible to make a poor connection using quality tools, it is virtually impossible to make a good connection using poor tools) IIRC this was a quote in a marine electronics book by a Dr Charles Wang apologies if the memory banks are corrupted.

If this is your first job, I recommend you work with a good marine electrician. As Ralph L would say, "the first thousand are the hardest". It takes a lot of practice to achieve results shown in the picture Solar Eagle posted

Thanks a lot for your input, and yes: as I am working on my 999th boat, I will hire a certified eletrician to supervise my job! :-).

Also thanks for the advise about Solar Eagle´s picture: I was about to search for an electron-eating dragon in the bilge!

My first question is do you have a steel or another hull material?

Is the hull and its other "wet" components suitably protected with full cathodic protection?

Simply linking all of the -ve cables could/should be OK as long as nobody has done anything silly....I would do it one link at a time, maybe with a heavy duty fuse as the link first......just a thought!

I do know that cars went from a +ve ground to a -ve ground, some say due to corrosion problems. I can believe that.

I would imagine that a boat hull must have similar problems....so do take good advice....

Linking all the grounds is what I would call normal......but as ever, I am prepared to learn more!

By the way, the OP is thinking in the old (conventional current) electron theory. Electrons actual go in the reverse direction......negative to positive!!

See here:-

http://www.allaboutcircuits.com/vol_1/chpt_1/7.html

Hi! The hull is made of steel, and (theoretically) adequately protected with a lot of $$ in anodes.

"By the way, the OP is thinking in the old (conventional current) electron theory. Electrons actual go in the reverse direction......negative to positive!!" I must recon, I´m an old fashioned guy who was born in the times lightnings fell from the sky, just the opposite they do today, as they are now said to leave the ground and climb into the clouds....

I think it was Benjamin Franklin who decided that current flow was positive to negative....so just how old are you?

Actually conventional current flow (the Ben version) is often still used when teaching certain electronics as for instance it makes understanding transistor operation easier to understand....strangely enough.

As long as the student is made 100% aware why, it should not be a problem....

But when working with valves (tubes) its easier to use REAL/PROPER current flow!!!

I use the one that helps me most when working, depending upon what I am doing....though I don't work with valves anymore, but I still keep my eye in on valve schematics.....

I think it was Benjamin Franklin who decided that current flow was positive to negative....so just how old are you? I´m 235 years old, why do you ask?

You should make all the -ve. terminals common. Since all batteries are 12 V, the battery that has drained the most will get the lions share of the charge.( as the voltage would be less than on the other batteries.)

You can also keep the hull isolated, and use a 2 wire system for all equipment and instruments.

Its probably better in such cases, to charge with mains voltage and a separate charger for each battery system....as running them all in parallel, as would be implied, would be really bad.....basically, then you only need one battery for everything......

I would suggest that though linking the negatives may be a good idea, I would leave the positives completely separate, as they are right now.

Thats my 2 cents.

Where do you get the mains voltage from on a boat? (And I may be wrong, but I don't think we're talking millionaire yachts here).

I believe the OP mentioned a mains generator......maybe I misread.....

I will check.

No, no mention of it as I could see quickly.......so forget the mains generator!! Sorry!!

There are 3 sources of 220V: one is the marina, when moored. The other one is a generator, and the third one is a 2000W inverter.

Ah, more information leaks out!

Never expect a millionaire to disclose all his secrets at once!

Brother, can you spare a dime?

you´ve either got or you haven´t got style! https://www.youtube.com/watch?v=xwCYBJe0o2M

I was right after all!!!

Mains is available!!!

Could get a bit unproductive if you're giong to charge the battery using a charger connected to the mains outlet of an inverter powered by the battery!

I did not read inverter, only that mains was available in one of three(?) ways.....which makes it easy to size the chargers for each battery set/size.....and keep them separate....

are you proposing a charging system based on Perpetual Motion?

on the contrary, I'm proposing that trying to construct such a system is not a good idea.

Actually only the negative terminal should be made "common".

The individual batteries would be charged at "place of use" meaning if it was an engine battery the battery would be charged by the alternator on the engine.

Keeping the batteries ( + ve terminal ) isolated is a good idea.

You wrote:-

Actually only the negative terminal should be made "common".

Not here, but there are situations where the plus and minus from two different batteries may be connected when for example a higher voltage is required....

Yes you are right, This is true when you want to put batteries in series to get higher voltage.

Consider the series connected batteries as "ONE" and the -ve. terminal should be made "common".

This will not be a problem if you are charging the batteries individually.

positive ( + - ..........+ - ) -ve

And then there are battery isolators, which I wont mention.

On many smaller steel hull boats, 75ft/25m or less, it is common to run a two wire system plus grounding the negative system to the hull through either a frame or some other fixture directly, securely and electrically to the hull. For the items with larger draws of electricity, engines, gen-sets, batteries, anchor chain winches, etc. these are sometimes connected together with non-insulated braided wire straps. For other smaller current units a wire of sufficient size is run to a junction point or switch and/or circuit breaker panels which then distributes the current to each individual power user. This is very similar in design as main electrical Circuit Panel and sub-panels in a residence are configured. This attachment to the hull and negative distribution through wires is similar in function and wiring as "bonding and grounding."

It would also be beneficial to use battery isolators between the different battery banks. These will isolate the batteries from each other when drawing electricity from them and allow them to be combined when charging them. This way one battery will not be able to draw from another battery but will be able to be charged together. For example the port engine starter will only draw from its battery so it will not be able to draw down the starboard engine battery. If the batteries were connected together it would be possible for one engine to draw down both batteries and there wouldn't be any power for either engine. This would make it so no engine could be started, not a nice thing since it is hard to get a jump start between boats.

Also, electrons know where to go. They just "Follow the Yellow Brick Road" to the lowest charged battery. Electrons are pretty smart for that.

Good Luck, Old Salt

great input!

I have gone through the responses. It was difficult for me to understand the seriousness of responses. Common Grounding of various systems ( in this case of different battery circuits) is required to provide a common reference potential point. At all the battery bank you have both the polarities available and pick up the reference point based on circuit details ( I mean +ive or -ive) For a common grounding you may have to take all the reference ground points of different systems to a common place and join them on a common Platform ( may bebus bar). If You are rewiring better consider an all around the boat conductor like we do in case of earthing of buildings/ panels, which can work as common grounding /Earthing for the boat, as it is DC. Please note that your system is basically 12 VDC. Please also note that the non-grounded ends of different systems MUST be isolated and remain within their specific circuits. It is not the current but the voltage cross-overs which causes the issues and that it self generates current. If non - grounded terminals are kept isolated ( no inter-system cross overs of non grounding terminal be allowed) there is no harm to your system. I didn't get about all the circumventing discussions made in the responses by various respondents.

They all have names and the gate keeper does allow the ones that don't belong there back in.

The electron does not belong to any particular atom. They are always trading places. In some elements more so then others.

The electrons are moving from the negative potential to the positive potential. They are responding to that difference in potential independent of the other batteries. Since there is no connection of the positive terminals of these batteries there is no imbalance.