Battery Wiring question

Don S/V ILLusion · Aug 5, 2012

If I correctly visualize what you did, the only difference between that and what you found in Calder's book is that you used more wire and more connections than necessary.

Paul F · Aug 5, 2012

Electricity is either connected or not connected. Your method is fine. It uses more wire but in that you already have the cables made up - you may as well use them. The wiring on my boat is half and half. The positive cables go directly to the battery switch and the negative cables go from battery to battery.

Stu Jackson · Aug 5, 2012

Quite frankly, I didn't understand a word of the OP.

You might want to read these:

Basic Battery Wiring Diagrams This is a very good basic primer for boat system wiring: http://c34.org/bbs/index.php/topic,6604.0.html

This is another very good basic primer for boat system wiring: The 1-2-B Switch by Maine Sail (brings together a lot of what this subject is all about)
http://forums.catalina.sailboatowners.com/showthread.php?t=137615

SEMIJim · Aug 5, 2012

Stu Jackson said:
Quite frankly, I didn't understand a word of the OP.

IIUC: He currently has separate positive and negative cables going from each battery, directly to positive and negative bus bars. He asserts that Calder's manual asserts that he should "chain" the cables from battery-to-battery, then a single cable, each, positive and negative, going to the boat's electrical system.

I'm pretty sure Maine Sail recommends it be done as he currently has it.

Jim

kenn · Aug 5, 2012

AlexLopez said:
what the impact of having wired the batteries as I had previously done would have on the batteries and or other systems.

The first concern is current-carrying capacity. If you used heavy enough wire, and your connectors, lugs etc are all appropriately sized, well crimped, etc, then there's no compelling reason to rewire the battery connections, in my view.

Having more wire means more places where accidental shorts could theoretically occur, but again if you've routed your wires carefully and they're well-secured, there's little chance for that.

More connections does mean more things to check, so be sure to examine and tighten your bus bar connections as part of your regular maintenance.

scotticus · Aug 5, 2012

I am an electrician. and although I mostly specialize in three phase 480/277 volt distribution systems I have on many occasion wired commercial universal protection systems U.P.S. also known as battery back up banks usually consisting of 12 to 24 12v deep cell lead acid battery's. The way you make battery connections is very important as connecting them incorrectly will change the properties of the bank from voltage to watt hours to dead short. you have with your wiring method created a parallel connection In the PARALLEL CONNECTION, batteries of like voltages and capacities are connected to increase the capacity of the bank. The positive terminals of all batteries are connected together, or to a common conductor, and all negative terminals are connected in the same manner. The final voltage remains unchanged while the capacity of the bank is the sum of the capacities of the individual batteries of this connection. Amp-Hours Cranking Performance and Reserve Capacity increases while Voltage does not. thus you have done it correctly..... Just make sure all connections are tight and are indeed parallel.

Stu Jackson · Aug 5, 2012

Wouldn't a wiring diagram help? Like, before and after...

Maine Sail · Aug 5, 2012

AlexLopez said:
Good morning all,

I am currently replacing my house battery bank and doing some clean-up and wire replacement. When I added additional house bank capacity a couple of years ago I ran wires from each of the 4 batteries negative terminals to a distribution bus and then ran one wire from that bus into the boats electrical system. I also did this with the positive terminals by running them individually to a separate bus then into the boats electrical system

I have been reading Calder's manual and see that he as well as all other sources indicate that the negative terminals should be tied to each other one to the next then into the boat as well as the positive terminals should be run similarly.

I intend to rerun the cables as Calder indicates however I wanted to ask if there is someone who understands what the impact of having wired the batteries as I had previously done would have on the batteries and or other systems.

We really need a wiring diagram to help you out. If you can draw one that would be an excellent start...

heluse · Aug 6, 2012

As long as the conductors (cables, crimps, buss) are of sufficient size to handle the amperage, electrically it doesn't make any difference. Mechanically, the more connections, the more chance for corrosion and such. If your present system is working, I would just leave it.

Fly_H23 · Aug 6, 2012

If all the batteries are physically located together there is no real advantage to "home running" each battery. Like other comments you're just using more wire. I would fuse each battery at or near each positive battery terminal. Just be sure the correct gauge of wire is used for the amount of current your system will draw.

I would personally parallel the batteries together where they reside then run larger gauge cables to the panel bus.

Stu Jackson · Aug 6, 2012

Fly_H23 said:
1. If all the batteries are physically located together there is no real advantage to "home running" each battery. Like other comments you're just using more wire.

2.I would fuse each battery at or near each positive battery terminal. Just be sure the correct gauge of wire is used for the amount of current your system will draw.

1. Agree

2. Nope, fuse each BANK not each individual battery.

onecoolair · Aug 6, 2012

AlexLopez said:
First thank you all for responding and trying to help out with our battery issue.

We have done something to shorten the life of our house bank and making certain that it is wired correctly with good connections is our first step in order to do good electrical tests with accurate results.

I have hand drawn two (Basic) diagrams for review. The first is of how the batteries are currently wired and the second indicates how I intend to wire them.

There are several obvious bits and pieces that I did not include since my drawing skills are not up to it and the components that I've omitted do not change the wiring path's.

Fuses for the Battery Bank, Inverter, wind turbine, windlass and solar array are installed in line but not shown on either diagram. Regulators for the Solar array, and wind generator are also installed. Data and voltage monitoring cables on the Link 20 battery monitor are also not shown.

as an aside the bus bar (indicated as Gnd. bus # 1) was added since the previously existing bus bar (gnd. bus # 2) .

Please take a look at the diagrams and let me know if you see something that is a show stopper.

Thanks,

Alex
S/V Nepenthe
Grenada

Why is your starting battery on the #1house and your house bank batteries on #2 start?? And "C" ??? Actually nothing looks right on both schematics. Sorry.

Stu Jackson · Aug 6, 2012

Alex, you may want to read the links I previously provided. Your proposed wiring makes little, if any changes, to what you already have.

Where you have "issues" is that you are using the 1-2-B switch as a charging selector switch instead of just a use switch. Read the links.

Run all your charging sources to the house bank, to the Positive Bus, including your alternator output. The ONLY things coming off your C post should be your starter and DC Distribution Panel. You could wire the second leg of the shorepower charger to bank 2. Wiring the shorepower charger to the 1 and 2 posts as just like wiring them to the positive bus bars nearer your banks, different ends of the same wire.

Going back to your original post, I'm not sure what the differences really are. You have bigger issues as far as your charging sources are concerned than merely bus bars. The second sketch (proposed) is a better way to wire your paralleled house bank batteries.

mjmercer19248 · Aug 6, 2012

AlexLopez said:
First thank you all for responding and trying to help out with our battery issue.

We have done something to shorten the life of our house bank and making certain that it is wired correctly with good connections is our first step in order to do good electrical tests with accurate results.

I have hand drawn two (Basic) diagrams for review. The first is of how the batteries are currently wired and the second indicates how I intend to wire them.

There are several obvious bits and pieces that I did not include since my drawing skills are not up to it and the components that I've omitted do not change the wiring path's.

Fuses for the Battery Bank, Inverter, wind turbine, windlass and solar array are installed in line but not shown on either diagram. Regulators for the Solar array, and wind generator are also installed. Data and voltage monitoring cables on the Link 20 battery monitor are also not shown.

as an aside the bus bar (indicated as Gnd. bus # 1) was added since the previously existing bus bar (gnd. bus # 2) .

Please take a look at the diagrams and let me know if you see something that is a show stopper.

Thanks,

Alex
S/V Nepenthe
Grenada

There is a thing called ground loops. It usually only affects sensitve equipment. It occurs when there are multiple paths to ground (negative terminal) if one of those paths becomes more resistant than another current can actually flow within the negative path (loop).

onecoolair · Aug 6, 2012

AlexLopez said:
Thank you for pointing out that I unfortunately mislabeled bank #1 and bank #2 in terms of which is the house bank and which is the starting bank.

Fortunately that does not substantively change the question and or the issue. In terms of your question regarding the letter designation "C" it refers to common.

Lastly, "Nothing looks right on both schematics" might be a bit of an overstatement.

Thank you for your feedback though on the other two issues.

Alex

No problem Alex ...Just trying to help. I would tend to agree to Stu's assessment. I would like to add though. So I could kill all power to starter motor I have a second 1/2/both/off selector switch make before break next to engine with a remote bipass button for emergency starting if yanmar cockpit instrustment panel fails. #1 is for starter battery #2 goes back to "C" post on main house 1/2/both/off make before break selector at nav. Extra alt wire to isolator next to engine switch. #1 post on iso to echo for starter battery. #2 iso to #2 battery post on selector. Main yanmar harness is left as is . All of its defect issuies have been resolved. Now I open the engine cover inspect engine turn battery switch on say #2 which goes back to house. Can start from start battery if needed. But leave on #2 so alt sees main house. Alt sees that bank and it gets first charge. Echo gets all power from alt. through isolator. This takes care of what little the starter battery will need. At end of day inspect engine again and shut things down by turning switch to off. Everything else like all other charging sources, 3 bank battery charger seperately to each bank and breakered. 10 amp Solar controller to house "C". If I ever get a wind generator I would put it on its on controller or use the same controller not sure yet on which way I would go. But the wind gen. would still only feed house bank on say "C" post. Or With something like anther echo from one #1 house to #2. Both main house banks are already isolated from each other. So?..Just thinking not quite that far yet.

jviss · Aug 7, 2012

Home run wiring

I immediately recognized what the original poster was asking, since i have just last week rewired my house batteries from a daisy-chained configuration to a home-run wired, i.e., star-wired configuration.

At the currents involved when charging from the engine alternator, this can make a difference. The statement that if

Despite what one commenter said, the second sketch is not a better way to wire the house batteries; it is a better way compared to daisy-chaining and taking both positive and negative to the loads off one end.

Assuming that all of the battery wires you used in the original configuration are the same gauge and about the same length, this is a superior configuration. The reason is that all of the batteries are the same electrical distance from the charging source and the loads, and therefore will be equally charged and discharged.

If you star-wire the batts and connect your alternator regulator sense line to one of the positive terminals, the batts, if they are all the same type, same age and same use history, will see essentially the same charging current and voltage.

There are other issues and questions regarding your diagram.

(I don't agree with Stu on how to wire the 1/2/BOTH switch, but that's minor; I connected "C" to the house loads circuit breaker, "1" to house batteries and "2" to the starter, which has its own battery through a disconnect switch).

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