Battery/Electronics for Dummies? -- Help Needed!

[Evan]

I recently purchased a 1975 CD25 and am struggling to understand the battery and electronic hook-ups. (While I've sailed all my life, this is my first time with anything electronic.) I have two deep-cycle 12V batteries and a standard "1,2,Both,OFF" battery switch. I have an outboard with an alternator, a compass, depth guage and speed log, VHS radio, and navigation and cabin lights. Everything is disconnected and, looking at the wires, it's not clear to me how they should be re-connected. Is there anyone who can explain IN VERY SIMPLE LAYMAN'S TERMS the standard arrangement for the batteries, alternator, battery switch and cables coming from electronics? My knowledge of electrical matters is just a hair above knowing how to change lightbulb. I need help! Thank you all in advance for any words of advice for this electrical dummy!

Evan
s/v CHLOE
CD25



eeames@aol.com

[Tom]

I recently purchased a 1975 CD25 and am struggling to understand the battery and electronic hook-ups. (While I've sailed all my life, this is my first time with anything electronic.) I have two deep-cycle 12V batteries and a standard "1,2,Both,OFF" battery switch. I have an outboard with an alternator, a compass, depth guage and speed log, VHS radio, and navigation and cabin lights. Everything is disconnected and, looking at the wires, it's not clear to me how they should be re-connected. Is there anyone who can explain IN VERY SIMPLE LAYMAN'S TERMS the standard arrangement for the batteries, alternator, battery switch and cables coming from electronics? My knowledge of electrical matters is just a hair above knowing how to change lightbulb. I need help! Thank you all in advance for any words of advice for this electrical dummy!

Evan
s/v CHLOE
CD25

Evan, The idea behind having a battery switch 1-2-Both is that you want to be able to shut off all the electrical systems when you are away or in an emergency. There should be nothing between the batteries and this switch except wires. The idea behind having two batteries is so that you can use one battery just for starting. It can be either of your batteries but you designate it as number 1 and that is the one that you will never run the radio on, or run the lights or anything that could run it down by accident. It is just used for starting the engine and should always be fully charged. Your other battery you will call number 2. You switch to this one when you are using the radio, reading at night, or sailing with running lights on and so on. Now if you accidentally run down battery #2, you are not stranded because you can then switch to battery #1 which has a full charge and start your engine.

Thus one of those big fat cables will run from the battery you are calling #1 and bolt to the terminal on the battery switch that is marked #1. This is the + positive cable which is usually red or is marked positive somewhere. The other of those big fat cables that is attached to the positive terminal of the other battery which you are calling battery #2 runs from the battery to the bolt on the battery switch that is marked #2. It is also the + or positive cable that is usually red or marked positive.

You now have a cable running from the positive side of what you are calling battery number 1 to the post marked 1 on your switch, and you have a cable running from the positive side of the battery you are calling number 2 to the post marked #2 on you battery switch. The other post on your battery switch is marked "COM" for common. You will attach a cable from this post to the positive side of your fuse panel. This is the tricky part because there are a lot of ways to do this. Someone who is familiar with wiring will see right away how it should go.

The other post on your batteries is marked - negative. This big fat cable is usually black and is marked negative in some way. On a boat that has an inboard engine these black cables usually run to a bolt on your engine. With an outboard they may run to a terminal somewhere that is marked negative.

The battery switch enables you to switch to "off" when you aren't aboard or in an emergency where you want to shut everything electrical off right away. Normally you will switch from "off" to "1" and start your engine. Let it run for a little while to replace the charge lost in starting. Then switch directly to "2" without going to "off" first. When running you normally leave it here. At the end of the day when you shut the motor off and want to start again you switch to "1" just to start.

The one thing you want to be careful never to do is cross the positive wires from the battery to the negative wires from the battery. This can start a fire or even explode the battery and throw acid everywhere in addition to damaging you and the boat. If you really are a complete novice with electricity, I'd highly recommend that you get someone to help you wire it up. It's easy to get confused with wires running everywhere and you don't want to accidentally do something stupid that will cost a lot to fix. A little mistake can lead to a big problem. Also there may be a reason that all the wires were unattached. Someone ahead of you may have crossed the wires and set up a dangerous condition that you will find out about when you hook up the batteries. I'd err on the side of caution here and get a knowlegeable friend or hire a marine electrician. If there aren't any major problems it should take less than an hour to do and is well worth the money to have a pro spend an hour with you. If there are major problems you wouldn't want to be fooling around with it yourself anyway. Good luck - hope this helps.



TomCambria@mindspring.com

[Neil Gordon]

>>There should be nothing between the batteries and this switch except wires.<<

Unless there's a bilge pump with an automatic switch. That should be wired directly to the battery so that the wire to the pump is hot even if the battery switch is off.

>>The idea behind having two batteries is so that you can use one battery just for starting.<<

A common practice, which I use, is to use both batteries to start, then run the electronics, lights, etc., off either battery 1 or 2, depending on the day of the month, odd or even. That way you get full starting power, both batteries charge while the engine is running and the batteries wear more or less evenly over time.


Regards, Neil
s/v LIQUIDITY
Cape Dory 28 #167



neil@nrgordon.com

[Tom]

>>There should be nothing between the batteries and this switch except wires.<<

Unless there's a bilge pump with an automatic switch. That should be wired directly to the battery so that the wire to the pump is hot even if the battery switch is off.

>>The idea behind having two batteries is so that you can use one battery just for starting.<<

A common practice, which I use, is to use both batteries to start, then run the electronics, lights, etc., off either battery 1 or 2, depending on the day of the month, odd or even. That way you get full starting power, both batteries charge while the engine is running and the batteries wear more or less evenly over time.


Regards, Neil
s/v LIQUIDITY
Cape Dory 28 #167

You're right, Neil, I use both batteries for starting also. I was just trying to give him the basic idea for two batteries without too many caveats and options since he seemed to be coming from a place of very little background, and requested a very simple explanation.

Tom



TomCambria@mindspring.com

[sloopjohnl]

now would be a good time to pick up a good multimeter(with alarm/buzzer) and have someone show you how to use it. it will be a friend forever.

I recently purchased a 1975 CD25 and am struggling to understand the battery and electronic hook-ups. (While I've sailed all my life, this is my first time with anything electronic.) I have two deep-cycle 12V batteries and a standard "1,2,Both,OFF" battery switch. I have an outboard with an alternator, a compass, depth guage and speed log, VHS radio, and navigation and cabin lights. Everything is disconnected and, looking at the wires, it's not clear to me how they should be re-connected. Is there anyone who can explain IN VERY SIMPLE LAYMAN'S TERMS the standard arrangement for the batteries, alternator, battery switch and cables coming from electronics? My knowledge of electrical matters is just a hair above knowing how to change lightbulb. I need help! Thank you all in advance for any words of advice for this electrical dummy!

Evan
s/v CHLOE
CD25

[JpSmith]

I recently purchased a 1975 CD25 and am struggling to understand the battery and electronic hook-ups. (While I've sailed all my life, this is my first time with anything electronic.) I have two deep-cycle 12V batteries and a standard "1,2,Both,OFF" battery switch. I have an outboard with an alternator, a compass, depth guage and speed log, VHS radio, and navigation and cabin lights. Everything is disconnected and, looking at the wires, it's not clear to me how they should be re-connected. Is there anyone who can explain IN VERY SIMPLE LAYMAN'S TERMS the standard arrangement for the batteries, alternator, battery switch and cables coming from electronics? My knowledge of electrical matters is just a hair above knowing how to change lightbulb. I need help! Thank you all in advance for any words of advice for this electrical dummy!

Evan
s/v CHLOE
CD25

Evan,

I also have a CD25 and was recently in the same situation.

Check out this website:
http://boatsafe.com/nauticalknowhow/electricity2.htm

Happy sailing

J.P.Smith CD25 183



artd@mindspring.com

[Ben Thomas]

I recently purchased a 1975 CD25 and am struggling to understand the battery and electronic hook-ups. (While I've sailed all my life, this is my first time with anything electronic.) I have two deep-cycle 12V batteries and a standard "1,2,Both,OFF" battery switch. I have an outboard with an alternator, a compass, depth guage and speed log, VHS radio, and navigation and cabin lights. Everything is disconnected and, looking at the wires, it's not clear to me how they should be re-connected. Is there anyone who can explain IN VERY SIMPLE LAYMAN'S TERMS the standard arrangement for the batteries, alternator, battery switch and cables coming from electronics? My knowledge of electrical matters is just a hair above knowing how to change lightbulb. I need help! Thank you all in advance for any words of advice for this electrical dummy!

Evan
s/v CHLOE
CD25

Evan, check out Nigel Calders Boatowners mechanical and electrical manual. you can view his website at. http://lincoln.midcoast.com~ncalder/manual.html


you may find this book a godsend for basic understanding of your d.c. system from the seacocks up. fair leads, ben



btlandscapers@imagina.com

[Evan]

Thank you all for your responses. Now I feel a lot more confident about deciphering all those wires and I'm sure I'll have my motor and batteries and electronics up and running soon. Thanks again.



Eeames@aol.com

[Bob Luby]

C. Plath published a book ( sorry, I don't have the title- it's on my boat.) that was great- I'll get the data tomorrow. very simple, clear explanations with lots of line drawings. It's not rocket science.

One thing it reccommends is, in addition to a multi-meter, is just a 12-volt automotive bulb in a socket with wires coming from each terminal, say 2 feet or so. Costs about a buck or two to make.

If there's voltage between two points, the bulb lights. If the bulb is bright, you have sufficient voltage ( and current ) to run something. If it's dim the voltage is low.

In a way its crudeness is an advantage. Besides it costs less when it falls overboard!



Rluby@aol.com

[sloopjohnl]

you're right on bob. it is commonly called a test light and they are about ten bucks at a NAPA store. great item for the first line of detection as to whether or not you've got juice going to where you want it to go. keep it in the tool box right next to the multimeter.

C. Plath published a book ( sorry, I don't have the title- it's on my boat.) that was great- I'll get the data tomorrow. very simple, clear explanations with lots of line drawings. It's not rocket science.

One thing it reccommends is, in addition to a multi-meter, is just a 12-volt automotive bulb in a socket with wires coming from each terminal, say 2 feet or so. Costs about a buck or two to make.

If there's voltage between two points, the bulb lights. If the bulb is bright, you have sufficient voltage ( and current ) to run something. If it's dim the voltage is low.

In a way its crudeness is an advantage. Besides it costs less when it falls overboard!

[Scott Ritchey]

One final note. See the CD25 schematic (wiring diagram) in the owners manual. If you don't have one, there's one online via thia site.

http://www.txdirect.net/users/cd27/



ritcheyvs@aol.com

[Bob Luby]

Here it is.

The 12 Vold Doctor's Practical Handbook

By: Edgar J Beyn

1983, C. Plath, North American Division
Annapolis MD.



Rluby@aol.com