Electrical Questions

[nineteensixtycaddy]

For those of you who are into the wiring,and playing with toys on boats... I've got a few questions.

This is all prompted by my working/playing with my 59 Evinrude Lark 35hp.

First of all, let me start by saying I've played with wiring for some time, mostly on cars, and have a very limited knowlege of how things really work. I sorta understand a generator with an external voltage reguator, and an alternator with an internal volgage regulator, and I know something about fuses and wire size/gauge, and a bit about relay's and switches.

That being said... first question, isn't a starter's solenoid... basically a heavy duty relay? The little wire going to the solenoid, trips the relay, to let the heavy duty positive battery wire, connect up to the starter. I've always wondered why they call it a solenoid, instead of a relay.

Next question. I know how a distributor works, sorta, but I know NOTHING about a magneto. I know a distributor needs to collect energy in a coil, and then "distributes" that electricity into each cylinder carefully timed by a rotating "rotor" how apptly named. So... in a magneto, it appears there are still coils, but one for each cylinder, instead of one for the distributor. So.. each coil builds up a charge, and fires it into each spark plug.. but since no battery is required... the charge comes from a magnet? hence magneto? Do I have that right?

So.... the magneto, requires no outside power, after it's rotating. Hence it needs a short, like the cutoff switch wires, to make it stop running. I get that I think.

My question is... why does a mageto powered engine, need a battery? The evinrude has a battery, going to the starter, and basically just uses the battery to start the engine. And that's all it really is there for right? So... how does the battery get charged?

That's my real question. How does the battery get charged again. I don't see an alternator, and haven't heard of one existing on outboards. And I don't have the "optional" generator that the 59 manual lists. So.. without a generator, or alternator... won't the battery just wear out after 4 or 5 starts, and refuse to turn the starter anymore. I know a car battery can only start a car so many times without being hooked to some sort of charging system, or else it goes dead.

Next question, very related to the previous... if I hook up stuff like running lights, a horn, interior lights, maybe a radio, how does the battery get charged to continue running all this stuff.

I can think of a few options here. Either I need to find a way to get the "optional" generator, which probably has about a 20 amp output, if that, compared to todays 150 amp alternators.

Or.. I need to find a way to mount and utilize a modern alternator and fit it in the hood of the lark.

or... perhaps the easiest method... I can mount two or more batteries, using one to start the motor, and the other to power my accessories, and have a "spare" in case either goes dead while out cruising for a day or two.

Or.. I'm way off base, and somehow the magneto charges the battery, and I have nothing to worry about!!!

Help Please

 

[tx1961whaler]

Re: Electrical Questions

1st question: A solenoid is basically a cylindrical electromagnet that is hollow in the center. In the center is a big piece of spring-loaded metal. When the electromagnet is "off", the metal rod inside does not make the connection between the positive battery connection and the starter terminal. When the electromagnet is "on" the rod tries to shoot out of the end if the cylinder. It then creates the circuit to the starter motor. The reason relays aren't used, is that a relay capable of reliably switching 100+ amps is huge and expensive.

2nd question: You basically have that correct. The flywheel magnet causes the coil to create the high voltage. And you don't need a battery for anything but the starter in these old twins.

I do not think that you have a charging system on your '59. They had a belt drive generator. I have a old 40 hp that used to have a generator, but I took it off because it's a pain in the butt to keep going in saltwater. I just use a deep-cycle battery and never had a problem, even over three days of fishing without recharging I also have the option to use a second battery, if the need arises.

 

[DutchMerc]

Re: Electrical Questions

some answers:
1. Your completely right about the starter-solenoid. It's just a big 1-pole relais.
2.Right again, the magneto gives a spark until it is shorted. It does not need any external power from a batery. You can even take the batery of when the motor is running.
3. The batery is just used to start the motor, and has no purpose when the motor is running. The motor is charged by a separate circuit, including a rectifier.
If your motor does not have this circuit, you will drain your batery when using lights, radio and stuff. You need to find a way to charge the batery.
I have a simular problem with my '74 Mercury and i am looking into the posibilaty to solar-charging. I haven't found a solution yet...

 

[drewpster]

Re: Electrical Questions

The term solenoid is normally associated with switches that perform a mechanical function by electrical means. The Ford type relays used on some outboards are in fact "relays". Solenoids are typically found mounted directly on starters and engage the starter drive gear and close the starter motor circuit.
Its kind of like the difference between a bushing and a bearing.

 

[Hitech]

Re: Electrical Questions

The solenoid that is on the starter itself is both a solenoid and a relay. The solenoid moves the starter gear into contact with the flywheel and then closes the contact between the battery and the starter windings.

 

[nineteensixtycaddy]

Re: Electrical Questions

Ok.. that helps a bunch. Thank you all. I now have a much better mental picture of the solenoid, and what it does. I will be ordering a proper marine solenoid for my motor soon. As to the issue with charging... I think I understand the magneto better now. I was curious about recharging the battery, and I now see that the only way that was possible, was with a seperate generator. Which, although an option in 59, my lark does NOT have. So... yes, running lights, horn, radio, etc will run down my battery. I like the idea of solar panels. Might have to look into that more.

Thanks again
Chris

 

[Silvertip]

Re: Electrical Questions

Solar panels are not a solution for battery charging on a boat. You would need one the size of the boat to do any serious charging and even then, it would be a target for thieves.

 

[drewpster]

Re: Electrical Questions

A solution could be to get a second independent deep cycle battery to run all your do-dads. Also get a decent charger you can use at home to keep the batteries up. If you do day trips to the lake a good deep cycle should be enough to keep the extras going. Of course the amount of time you get using your extra stuff depends on the stuff and how long you use them.

 

[nineteensixtycaddy]

Re: Electrical Questions

Well, as my boat will most likely only be used for day trips, and occasionally for a night ride, such as the 4th of july, or a twilight cruise, I feel fairly confident that having one really good deel cycle, or a couple standard batteries, one for the start circuit, and one for the "toys" and lights, should be plenty. I've had a 900cca optima in my 60 caddy since 2002, 6 years ago. That battery has cranked the caddy for two years, and then sat for a couple years, and then cranked it again. I recently just swapped it into my van, as it's battery, a 5 year old, died. The optima is still holding a fine charge. I can run the van's radio for 4 or 5 hours, with the headlights on to play basketball for 2 or 3 hours, and then get in and crank it up to go home. I'd imagine with a similar strength battery, running a radio and boat lights for 3 or 4 hours at twilight or the beginning of the night should be something a deep cycle battery can handle. Plus, in the worst case scenario, at least I have a pull start and magneto, so I can get home even if niether battery has anything left. or am I off track?

 

[DutchMerc]

Re: Electrical Questions

I think I'll be getting a second deep cycle batery and replace my standard lights by LED's. I hope i can keep the radio on and the CB standby for at least 4 hours. This will be the average time i will be fishing. (wish I had some more time to spend sometimes)...

 

[nineteensixtycaddy]

Re: Electrical Questions

I'm gonna have to agree with the two battery idea, a normal starting battery for the outboard, and a good sized deep cycle for the radio/lights/and horn. I looked at diagrams for both, and feel fairly confident I can handle this.

Thanks again to all the input, and I'm anxiously awaiting coils and a solenoid, to check this puppy out