1999 Yamaha Rectifier (Regulator?)

[starrzo]

Hey guys,

I've added some lights and wiring in and shortly I'll be adding a fish finder to my Orkney Coastliner. Yesterday I fired up the engine to monitor the volts with my new lights switched on while the motor charged the battery but I noticed that the voltage started around 12.8 then kept going up. The motor was just idling for around 10 minutes and I knocked it off where the voltage had climbed to 15.3. I'm not even sure how much it might have increased if I kept running or if I had added some RPM. Before this test I had assumed it would have regulated itself, so then I studied the parts catalogue on the Yamaha web site.

It looks like mine has a 'Rectifier Assy' where the other kind is a 'Rectifier and Regulator Assy'. That would explain the lack of voltage regulation. Do you guys think I could simply get a the Recitifier/Regulator using the part number below and fit it, which would hopefully regulate the voltage? Or would this cause any bother with my stator or anything? There don't seem to be any variations in generators in the parts catalogue. There are loads of cheap Rec/Regs to replace that part number on eBay that look like they would do the job, but I am no expert.

I have a little Motobatt 'absorbed glass mat technology' battery that I'd like the motor to keep topped up without causing any bother at high voltage.

Mine is the one on the right described as 'Rectifier Assy' and the one I'm proposing to switch to is on the left described as 'Rectifier and Regulator Assy'.

 

[starrzo]

Ordered this from China which promises to
regulate the voltage. I’ll see how that goes

 

[snowbird30ds]

If there's any distance to the battery run the ac cables from the stator to the battery box and fit the rectumfryer there and get a better charge before it cuts out.

 

[starrzo]

If there's any distance to the battery run the ac cables from the stator to the battery box and fit the rectumfryer there and get a better charge before it cuts out.

Is the implication here that my cheap chinese rec/reg is going to fry my rectum then die a death?

 

[snowbird30ds]

Is the implication here that my cheap chinese rec/reg is going to fry my rectum then die a death?

It depends where you mount it and how far you push it in.....

 

[jrudge]

I don't know the boat, but I assume it has nav lights, potter etc which are all powered by the current 12v supply?

If so then that supply will ( or should be) already regulated.

The alternator is usually regulates charge voltage.

If for any reason this is not the case with your boat then you will need some form of regulation.

I have used cheap Chinese droppers ( 24v to 12v ) which are basically regulators, and some are fine, and some are very poor and get very hot.

I would purchase a decent one that has ample headroom for the load you will put on it. Also bear in mind that the alternator will have a rated output which you should not exceed. Install a simple fuse / breaker board. They are on eBay.

Make sure the wires are thick enough. As current rises in a low voltage system the wires need to be thicker than you might imagine. Finally get tinned copper wiring. Copper in a boat will turn to dust in a remarkably short period.

 

[snowbird30ds]

I'm pretty sure it's on an outboard so not a normal alternator, likely just a couple of windings so needs rectifying first before regulating.

 

[Rappey]

It looks like mine has a 'Rectifier Assy' where the other kind is a 'Rectifier and Regulator Assy

Could it be that one version has just enough power generation to power itself. The other version has a greater output from its stator to give a current output for auxiliary items?