Additional Rectifier/Larger Rectifier Mod?

kungpaoshizi

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Anyone know the voltage/amperage off hand the stator puts out and if it's not possible to add a 2nd rectifier in the circuit, to upsize the rectifier to one to obtain more current output? Heck, even run a 2nd, to a secondary battery setup..
I have yet to see maxes on the parts..

Thanks!
 

Texasmark

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Dec 20, 2005
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Re: Additional Rectifier/Larger Rectifier Mod?

Look at the color of the stator. The red stator is the largest current capacity of the 3 and 4 cylinder engines according to the service manual. It is rated at 16 amperes. Just because it's rated for that doesn't mean it will run that for 24/7....that is a peak output number. You can double up on rectifier/regulators, but the stator coils still have loss and there is no cooling under the flywheel. Over time you will melt the insulation on the pickup coils of the stator and have a short circuit killing your charging circuit.

The other thing is that each of your separate rect/regls needs to feed a separate battery. If you feed 2 to the same load, the regulators in each will get confused and try to correct itself for a variance in the other one. You just don't want to do that.

Really man, a bad idea, but it's your boat and your money.

HTH,
Mark
 

kungpaoshizi

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Re: Additional Rectifier/Larger Rectifier Mod?

Pickup coils?
I thought a stator was basically abunch of coils around magnets leading to wires that goto the rectifier, that produce current by spinning around when the flywheel moves?
 

Chris1956

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Re: Additional Rectifier/Larger Rectifier Mod?

Kung, Your motor '77 1150 puts out about 9Amps at high speed. There is no way to upgrade that, without a custom-built stator, which I have never seen. If you were to upgrade to more current, you would need a voltage regulator to keep from cooking the batteries.
 

Faztbullet

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Re: Additional Rectifier/Larger Rectifier Mod?

You can double up on rectifier/regulators,
You have to have a separate output from stator to each rectifier, that why a 40 amp system has 4 yellow wires..
There is no way to upgrade that, without a custom-built stator, which I have never seen.
The stator coils would have to be larger and that would involve a custom flywheel as you need bigger coil windings/magnets to produce more volts/amps....
 

Johncs

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Jul 30, 2013
Messages
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Re: Additional Rectifier/Larger Rectifier Mod?

Anyone know the voltage/amperage off hand the stator puts out and if it's not possible to add a 2nd rectifier in the circuit, to upsize the rectifier to one to obtain more current output? Heck, even run a 2nd, to a secondary battery setup..
I have yet to see maxes on the parts..

Thanks!

DON T EVEN THINK ABOUT IT,stator/rectifiers are designed for a certain output and should not be re-designed,,,,even keeping a battery switch on 2/both batteries while running will definitely blow the rectifier and possibly the stator
 

Chris1956

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28,102
Re: Additional Rectifier/Larger Rectifier Mod?

John, A rectifier will not blow if the stator cannot exceed it's current or voltage spec. In this case that is exactly what we have. You can connect it to as many batteries as you want, as long as they are connected in parallel, so the voltage is 12VDC. If you short the rectifier or disconnect it from the battery it will pop nicely.
 

Johncs

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Re: Additional Rectifier/Larger Rectifier Mod?

yes I agree and the reason I stated that was from experience on several outboards i had to replace rectifiers and or regulators on them and they all had stated prior to the battery not charging they ran their bat switches on 2/all.I work on a lot of different type of items and enjoy the satisfaction of diagnosing difficult repairs.Y ou have a lot more exp than me on outboards and that is one thing that is very important and you should be very proud of it. thanks john ANY INFO ON TESTING A REV LIMITER WHEN ENG WON T GO TO HI RPMS?
 

kungpaoshizi

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Re: Additional Rectifier/Larger Rectifier Mod?

If you short the rectifier or disconnect it from the battery it will pop nicely.

The rest of that is "if the motor is running" correct?
 

Lowell_B

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Jun 3, 2013
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Re: Additional Rectifier/Larger Rectifier Mod?

Ok... having picked up a '93 Black Max 135, and going through numerous issues with it, I'm down to rectfiers/regulators (of which it has two). Now seeing how this assembly is $400+ and I'm cheap, I started wondering. Why couldn't you use a simple auto voltage regulator (about $25/each) in place of the existing ones?
SI_VR20_Front.jpg

It seems like connect yellow wires to "ARM" and "FLD", then the red wires to "BAT". Of course, since I have two regluators on the Max (with four yellow wires) I'd have to install 2 regulators.

Anyone ever tried this? A heck of a lot cheaper than the Mercury option. Curious to hear what you might have to say.
 
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Faztbullet

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Re: Additional Rectifier/Larger Rectifier Mod?

Thats a regulator for a generator (DC) not a rectifier/regulator(AC). That unit does not have the diodes to convert AC to DC, in other word dont even try it...
 

kungpaoshizi

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Re: Additional Rectifier/Larger Rectifier Mod?

Just a guess Lowell, but I'm assuming the Mercury's are specifically engineered for moisture protection? (that's why a lot of auto parts aren't to be used?)

Idk for sure, pretty new to boating myself, but I have seen a TON of corrosion inside my wires etc on my 77, so I'm assuming moisture is a bigger problem than not over time..
 

Chris1956

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Mar 25, 2004
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Re: Additional Rectifier/Larger Rectifier Mod?

Kung is correct as is Fazt. The Marine VRs are potted with an epoxy material. Most Marine OB stators are two wire, whereas auto/sterndrive/ and some DI OB's alternators are 3 phase and require a different kind of VR.
 

Lowell_B

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Re: Additional Rectifier/Larger Rectifier Mod?

Thanks and I do know the difference. I have two 40 amp rectifiers (sealed) mounted to heat sinks in place. Guess I'll just bite the bullet for the Merc parts or sink the dang thing! LOL I just hate such markup on parts. Commercial grade 40 amp rectifiers are $8 a piece. Add a $2 piece of heat sink and you've turned AC to DC with a unit that will stay cool (which is the biggest problem anyway) and is just as corrosion proof as the original unit. Still searching for a solid-state 13.8 vdc regulator (at about 10 amps). Long story short, I can build a reliable unit for about $20 (once I find the regulator component).
 
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Chris1956

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Re: Additional Rectifier/Larger Rectifier Mod?

Lowell, While what you have described is accurate, you would end up with a open charge device which would cook your batteries. The expensive part of the VR is not the diodes or heatsink. It is the regulator circuitry. A DC-DC converter would work, but cannot handle the current of the charging system (40A). BTW your motor should have twin 20A VRs, each with it's own yellow stator leads. CDI makes replacements, which are cheaper than merc, and some claim are better. I needed to replace my OEM VRs when I got my '93 Merc 135HPV6. The burnt up, one at a time. I bought the CDI versions and so far so good. I put a voltmeter on the battery to make sure it was charging. The voltage was all over the map. But the battery stays charged.
 
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