Newbie Question about alternators? VOLTAGE?

[cturboaddict]

Okay, im pretty new to outboards and had a question. NOTE~im in the process of restoring a boat, and will be wiring it here soon.
Ive got a 1971 85hp Evinrude with the selectric shift... (thats what i have for now until more funds arrive to replace)

Okay~
How does the charging system work on an outboard? Any diagrams WOULD BE AWSOME! It doesnt have an alternator like a car engine... SO??? How does it charge?
What kind of amperage does the motor put out to charge the battery? Does it supply enough power to run the nec electronics (radio/lights/???) while the motor is running? Or does it just put out enough to charge the starting battery?

If i decided to run a two battery setup... Would this be more beneficial to me? ALso, would this motor be able to power two batteries for charge when out on the water...

Ill be running the usual accessories... (stereo/bilge/nav lights/dash lights/tilt-trim/12v cig/stern light) and possibly if able to on the power i have an amplifier for the stereo. Ill probably be listening to tunes while cruising, and if we stop to float probably play tunes while relaxing...

 

[Silvertip]

Re: Newbie Question about alternators? VOLTAGE?

The alternator on an outboard is similar in operation to that of an auto alternator except it is built into the engine -- located under the flywheel. The flywheel has magnets around its perimiter. A stator (a collection of poles on which coils of wire are wound) generate the electricity as the magnets pass by each pole. This creates "alternating current". A rectifier converts the ac current to dc (direct current). If the engine has a voltage regulator it is installed after the rectifier to maintain the output voltage at safe levels and to prevent over charging the battery. Many older outboards did not have regulators since the alternator output was not high enough to overcharge the battery.

In your case, the alternator output is relatively low (don't know the exact output) so you will be limited as to what the electrical system can handle. However, if you have two batteries, one can be designated the "house" battery while the other is the engine or "starting" battery. There are many ways to incorporate a dual battery setup but the simplest, most versatile, and least expensive is a dual battery switch that lets you select BAT 1, BAT 2, BOTH, or turn the entire system OFF. The switch has three terminals on it. BAT 1, BAT 2, and COM. BAT1 POS connects to BAT 1. BAT2 POS connects to BAT 2. The negative terminals on both batteries are tied together. ALL boat-side electrics and the large red battery cable from the engine go to the COM terminal on the switch. It works like this: OFF = all electrics are off. BAT 1 = you can start the engine on BAT 1, run all accessories on BAT 1 and ONLY BAT 1 will charge. BAT 2 = same as BAT 1 but using BAT 2. BOTH = You can start the engine using both batteries, both batteries power everything and both batteries will be charged with the engine running. The limited output of your alternator however would suggest that when running, you select the battery that is discharged the most. This gets that battery topped off first. Using BOTH would take considerably longer to charge. Also be aware that if you suck 15 amps out of any battery in say an hour -- you would need to run wide open for an hour to put that energy back into the battery. So -- it is common practice to install a two output on-board charger so you can plug into ac power at the dock to always ensure batteries are topped off. Here is a dual battery switch diagram. There are many ways to do this and there are also ACRs, VSRs, isolators, etc., but this is simple, cheap, reliable, and versatile.

 

[jhebert]

Re: Newbie Question about alternators? VOLTAGE?

For a description of how the charging system of an outboard motor operates, please see my articles

Boat Electrical Power Generation
http://continuouswave.com/whaler/reference/electrical.html

and

Permanent Magnet Alternators
http://continuouswave.com/whaler/reference/PMA.html

These two articles describe in detail the method of electrical power generation used on outboard motors.

 

[jhebert]

Re: Newbie Question about alternators? VOLTAGE?

Silvertip writes:

"The alternator on an outboard is similar in operation to that of an auto alternator except it is built into the engine -- located under the flywheel."

This is misleading. Most outboard alternators which are located under the flywheel are permanent magnet alternators. Most car alternators are not permanent magnet alternators.

There is a substantial difference in their operation, particularly with regard to voltage regulation.

 

[cturboaddict]

Re: Newbie Question about alternators? VOLTAGE?

That engine didn't have an alternator and relies on a flywheel stator for voltage supply. Be aware, on a good day at cruising speed it "MIGHT" produce 5 amps. Plan your electrical load/use accordingly.

If you are using two batteries, plan on investing in an on board charger.

Not a problem, i was figuring on doing one anyhow as their not too expensive for one....
As i was reading the post, i know that on my motor~the spark plug wires come from under the flywheel? So im thinking where are all these parts?? I know there is an "amplifier" on the back of the motor... But thats all i see.

 

[cturboaddict]

Re: Newbie Question about alternators? VOLTAGE?

For a description of how the charging system of an outboard motor operates, please see my articles

Boat Electrical Power Generation
http://continuouswave.com/whaler/reference/electrical.html

and

Permanent Magnet Alternators
http://continuouswave.com/whaler/reference/PMA.html

These two articles describe in detail the method of electrical power generation used on outboard motors.

Thanks for this, this does help me understand a bit better. Im just trying to see where the power from the coils/flywheel connect as a feed back to the battery now Is that what the amplifier is for on the back of the outboard?

 

[Silvertip]

Re: Newbie Question about alternators? VOLTAGE?

Simplicity was the idea in my description. Whether you have a magnet spinning past a coil, or whether you have a coil spinning inside a magnetic field doesn't matter. The result is generated electricity. Likewise, voltage regulation is voltage regulation. Dozens of ways to accomplish it. Again -- simplicity was the idea. Most folks have a bit of a clue how an auto alternator works because they can see it. The engine spins it. On an outboard you cannot see it so the posters question was very valid.

 

[jhebert]

Re: Newbie Question about alternators? VOLTAGE?

...voltage regulation is voltage regulation. Dozens of ways to accomplish it.

Those two statements seem paradoxical. If there are "dozens of ways to accomplish voltage regulation," it seems difficult to accept them all as the same, which I believe is precisely what is implied by saying "voltage regulation is voltage regulation."

My point is there is a distinctive difference between an automotive style alternator and an outboard permanent magnet alternator in the technique of voltage regulation, and this should be recognized. The permanent magnet alternator typically has a separate and external assembly that performs the voltage regulation. An automotive-style alternator typically has an internal mechanism which regulates the voltage output (by modulating the exciting field current). This is an important difference to understand and should be made clear. I do not think it is a good idea to try to obscure this significant difference by saying "voltage regulation is voltage regulation."

Re the "amplifier," I don't know what this term might refer to in a battery charging system. The elements of a battery charging system based on an alternator are typically:

--source of alternating current (hence the term "alternator")
--rectifiers to convert alternating current into direct current
--voltage regulators to control voltage output from the charging system

The battery charger circuit is typically not involved in the generation of ignition spark voltages. High-voltage ignition spark is generated by a separate circuit. If you need help understanding how outboard motors generate high-voltage ignition spark, please start a new thread. Let's leave this one focused on your inquiry about alternators.

 

[Silvertip]

Re: Newbie Question about alternators? VOLTAGE?

I'm sure the OP is now wondering what the heck he got himself into. Fact: The charging system on "most" outboards these days consists of the three parts 1) the alternator (excuse me -- the stator), 2) the rectifier, and 3) the regulator. Each performs the functions previously described. Add the magnets in the flywheel but they serve two purposes (charging and ignition power generation).

Fact: some small outboards have a lighting coil but no rectifier or regulator. Can't charge a battery but can be used to operate lights since lights can operate on ac power.

Fact: Some outboards have an alternator and rectifier but no regulator. Called an unregulated system but can be used to charge a battery.

Fact: Auto charging systems are "similar" in that they have an alternator, rectifier and regulator. It so happens, but is of no importance, that all three are generally combined into a single package called an alternator. These components are separate pieces on an outboard. in some cases the rectifier and regulator are combined into one package and in others they are separate pieces.

So: Alternators generate ac, rectifiers convert it to dc, and regulators regulate the output. Are the internals of each component "identical"? No! Are they the "same"? No!
Are these components "similar" in purpose? Absolutely! Which is where this all started.

Charging systems designed by two different engineering groups will likely never come up with exactly the same "design". Similar perhaps -- but not the same or identical.

Amen - Peace

 

[cturboaddict]

Re: Newbie Question about alternators? VOLTAGE?

Sorry guys sorry guys, maybe i should of been a bit clearer....
Okay- LET ME REPEAT BACK what im learning, and trying to learn. BE EASY on me here.... Here is my take~(laymans terms)

Were speaking of outboards in general, and mine to be more specific!
1971 Evinrude 85hp

So under the flywheel is what basically acts as the alternator. Which is really a stator. That is where my electricity is produced. Now from there it travels to a Rectifier. Then to a Regulator. Then back to my battery to charge???
CORRECT????

Now, where is the regulator located. Where is the rectifier located? And which wire should properly trace back to my battery for recharging? What does it come back off of? And will it be safe enough for me to run my radio while cruising? Im going to upgrade my outboard in due time, but will it be fine for me with my current motor to run dual batteries? So that when stopped i can still listed to tunes and float?

As for the amplifier that i asked about, after looking at some parts catalogs on line, I think its a "booster" pack of sort to provide power to the coil for spark? But im a bit unsure of where the coil is located anyhow?

 

[cturboaddict]

Re: Newbie Question about alternators? VOLTAGE?

I'm sure the OP is now wondering what the heck he got himself into. Fact: The charging system on "most" outboards these days consists of the three parts 1) the alternator (excuse me -- the stator), 2) the rectifier, and 3) the regulator. Each performs the functions previously described. Add the magnets in the flywheel but they serve two purposes (charging and ignition power generation).

Fact: some small outboards have a lighting coil but no rectifier or regulator. Can't charge a battery but can be used to operate lights since lights can operate on ac power.

Fact: Some outboards have an alternator and rectifier but no regulator. Called an unregulated system but can be used to charge a battery.

Fact: Auto charging systems are "similar" in that they have an alternator, rectifier and regulator. It so happens, but is of no importance, that all three are generally combined into a single package called an alternator. These components are separate pieces on an outboard. in some cases the rectifier and regulator are combined into one package and in others they are separate pieces.

So: Alternators generate ac, rectifiers convert it to dc, and regulators regulate the output. Are the internals of each component "identical"? No! Are they the "same"? No!
Are these components "similar" in purpose? Absolutely! Which is where this all started.

Charging systems designed by two different engineering groups will likely never come up with exactly the same "design". Similar perhaps -- but not the same or identical.

Amen - Peace

Yes sir indeed, thanks for that. Umm, as stated in my post above, how do i know if i have all or some or one of these? Its raining right now, but tomorrow morning ill take another look so that i can start to understand things a bit better. Im just trying to learn.. That all!
And thanks everyone for helping me!

I understand automotive alternators, and i see the similarity in the outboard motor. I also understand how voltage regulators work on automotives. Im a ford guy~trust me ive replaced a few... Im just staring at my motor scratching my head, thinking??? "how does it work", "will it power my lights/radio", "is it safer to have two batteries?"

I know sometimes you can sit with your car stereo on and listen, but that a bit different with a no start condition there due to a dead battery vs. a dead battery on the water...

 

[Lyle29464]

Re: Newbie Question about alternators? VOLTAGE?

You should have 2 yellow wires coming from the stator They hook into the rectifier from that I believe output goes to your starter solenoid. I might be wrong but I dont think your engine had a voltage regulator. If so I would run a duel battery setup or at least a large battery.

 

[Silvertip]

Re: Newbie Question about alternators? VOLTAGE?

To locate charging system components start at the battery and work backwards. If one does not know what a coil looks like or where it is at, one does not probably know what a rectifier, regulator, or rectifier/regulator looks like either. So -- follow the large battery cable from the positive post on the battery to the engine. That cable will termiinate on the starter solenoid. On that same terminal will be a smaller gauge wire. That wire ultimately originates at the rectifier, regulator, or rectifier/regulator depending on what the engine was manufactured with. If it has no regulator, that wire comes from the rectifier. If it has a separate rectifier and regulator, it would come from the regulator. If it has a combination rectifier/regulator it comes from that device. Since the motor is soon to be 40 years old it is hard to tell what it's previous owners have done to it.

Since the charging system output is apparently very low (5 amps or so according to one poster) that is just about enough to keep the starting battery charged and to run instrument and navigation lights. If you install a stereo system with an amp, you best have another battery and forget about keeping both charged from the engine. YOu will need an on-board charger to plug in at the dock or at home.

Follow the spark plug wires backward to locate the ignition system components.

 

[cturboaddict]

Re: Newbie Question about alternators? VOLTAGE?

Thank you guys on that tip on whats the path of wires...
Im going to go step outside and take a look at it, and ill post back if i have anymore questions...
THANKS AGAIN~ bear with me, im just trying to learn as much as i can.

 

[cturboaddict]

Re: Newbie Question about alternators? VOLTAGE?

okay, although it may sound it- im not that much of an idiot. I did as you said and traced back. Took pictures along the way, and tell me if im right.
Here is the starter solenoid with the lead battery wire connected. I see on the top the wires connected at the same terminal as the main feed along with the two "yellow" wires connected also.

Follow that along, and it ends up at the power distibution box. Under that is two things.... Im assuming one is the rectifier, and one is the regulator? Correct

Under that is the "amplifier" as i speak of that runs up to the coil to feed spark out... Correct.

Then the coil...

On to the distributor

Now~~~ Do you guys have a better clue of what will be my power output on this engine to charge the battery??? And also, does the power feeding back to the battery return on just the large red power wire from the battery or is it one of the smaller wires heading back through the harness? If it is, which feed does it come off of the distribution block?
That should be the end of my questions.........Really, it should....

 

[Lyle29464]

Re: Newbie Question about alternators? VOLTAGE?

with out looking it up I believe the "gross" output will be 9 or 10 amps.

That would be at 5500 or so RPM If you cruise at 3500 ( not a bad rpm for a 40 year old engine) you will be charging about 6 or 7 amps and the engine systems will use about 2 of them.


The charge does return to the battery by the main cable. The small red wire next to it goes to the output of the rectifier.

 

[Silvertip]

Re: Newbie Question about alternators? VOLTAGE?

The power to start the engine goes FROM the battery TO the engine on the large POSITIVE battery cable. Power from the charging system goes TO the battery via the same large battery cable so this is a two way street. If you look at the solenoid, the terminal that large red cable is attached to has the red charging lead also connected to it. Why bother running another wire from the same location all the way to the battery since there is already that large one. The AMPLIFIER is NOT the regulator for the charging system. The silver thing under the terminal strip is the rectifier. I don't think that motor has a regulator because of the lower output.

 

[cturboaddict]

Re: Newbie Question about alternators? VOLTAGE?

@Silvertip, whats next to the rectifier then (the rectangular box).....
Okay, i know that was my last question for real this time...

And once again guys, Thanks a bunch for clearing up this confusion for me. I just want to know how things work before i dig into them. This motor should suffice for now, until funds come around a bit better hopefully before spring. But until then, im still going to plan for a dual battery setup and an onboard charger too. Shouldnt be too complicated to wire up, and ive got a great place for both batteries and mounting of everything. I built a hatch for the back for the tank and storage for batteries!

 

[Silvertip]

Re: Newbie Question about alternators? VOLTAGE?

Ignition Amplifier! Since you are relying on us to look up specific details on your engine I suspect you intend to work on it yourself. Therefore I suggest you obtain a factory service manual for this motor. It saves time, tells you all you need to know about the motor and its systems, how to diagnose and replace parts, contains wiring diagranms and it will save you a ton of money because you won't make costly mistakes replacing things that don't need replacing or screwing up other things in the process.

 

[cturboaddict]

Re: Newbie Question about alternators? VOLTAGE?

Hmm, so there's TWO ignition amplifiers? Im not speaking of the large black box that says "AMPLIFIER" on it. Im speaking of the smaller black box next to the rectifier bolted down. Not the box below the rectifier, the box to the right of it---What is it??

Yes, im waiting on my "manual" to come in the mail~ I just ordered one.
And of course Ill be working on it myself, i dont think ive ever had any vehicle/motorcycle/boat anything ever dropped off at any repair shop for any reason? Wait, i take that back~ I dropped off my mustang for an alignment after new ball joints and upgrading the suspension ONCE.