Need a new alternator

[HarrisonM]

Hello:

I have a Beneteau 473. The alternator on my engine is some odd after market one. Currently it is not charging correctly and I want to replace it with something better. I have been looking at the Balmar 100 amp series 6 with the MC-618 external regulator for best charging. Curious if anyone has any good recommendations... Balmar's do seem a little pricy.

Harrison
Tarpon Springs, Florida

[JimsCAL]

Yes Balmars are pricey. Not many other options that are less expensive and offer similar capability. The least expensive option would be to take the alternator to a shop and have it rebuilt. Any shop that rebuilds auto and truck units is just fine.

[jimgies]

I just replaced a damaged alternator with an externally regulated one, then using a MC-618 with alt & bat. temp. sensors. Get the highest amp alt. that will fit your engine. A good alternator shop is key for the correct alternator

[cr180]

While Balmar alternators are more expensive, they offer a unique capability. They output near rated current (amps) at low rpms unlike automotive style that require near full rpms. This affords the advantage for a cruising boat to charge batteries at rated alternator output with the engine at idle speed while at anchor.

[jimgies]

The Cummins alternator I rigged up yesterday using a MC-618 was putting out 127 Amps @ 1100 RPM

[cr180]

Originally Posted by JIMSMARINEELECT

The Cummins alternator I rigged up yesterday using a MC-618 was putting out 127 Amps @ 1100 RPM

Understood. Rewiring an internally regulated alternator with an external Balmar regulator is what you’ve described. Agree reasonable approach for Alternator Shop. But since using Balmar regulator either way, a do it your self cruiser could buy the Balmar alternator and save the rewire shop labor.

[alamoana]

I used a Prestolite 8MR alternator 90 Amps or 110 Amps,,for 20 years and never had an issue with them. They were externally regulated by an Amplepower SARV3. Good luck

[HarrisonM]

Thanks for the great replies!!!!!

The alternator is an auto grade alternator the previous owner put in. Last summer I did some engine work and I did get it rebuilt. I think it is 55 amps so not the best for charging 2 house banks. When they gave it back to me the shop said it was some generic type they really had not seen before too. I am refitting her for a trip across the Atlantic in a few years. I want a high output alternator to charge up the house banks at relatively low rpm so I don't burn up a lot of fuel. I had not really thought of Cummins or Prestolite. I will look into those.

Thanks

Harrison
Tarpon Springs, Florida

[SV Confianza]

We have balmar xt170s and have been happy with the performance as well as their customer service. We had one die on us within the first year, and they repaired it fairly quickly.

[Senojev]

The Cummins alternator is likely a Delco Remy. I upgraded my alternator to a Delco 28SI 200A which produces 140A at idle. Cost around $300 about 6 years ago. It was about $75 to convert to external regulation. Check out the SI series as they have smaller alternators in the series.

[Bowdrie]

Originally Posted by alamoana

I used a Prestolite 8MR alternator 90 Amps or 110 Amps,,for 20 years and never had an issue with them. They were externally regulated by an Amplepower SARV3. Good luck

Yep, I'm completely satisfied with the performance and quality of build of the Leese-Neville/Prestolite alternators.
Sometimes they might not advertise the highest output ratings per frame size, but they are real heavy-duty units that will give their rated output under duress and at relatively low rpm.

[Tsuru]

If your current alternator is a single belt consider a belt upgrade. 100 amp is about max for a single belt, even so it will go through belts quickly.
https://pbase.com/mainecruising/electromaax_kit

[Mickeyrouse]

I have used Balmar alternators about 15 years. I haven’t had to re-build them more than about every 100 hours, which is why I cruise with a spare. I have never had trouble with the regulators, but the alternator diodes constantly fry. I recently had them converted to “ single wire”, thus bypassing the external regulator and using the internal regulator. My alternator repair guy says that makes it a Delco alternator now, which is fine as long as it is more reliable. It has been, and if I have to replace it a Delco-type replacement is about $109 at Autozone.

[NYSail]

I installed a balmar 150 amp with mc-614 about 5 years ago (pre mc 618 days) on my beneteau 423. Also installed a serpentine belt. Great product. I bought it from Rod (mainsail) and he gave gave me all the settings to make it work efficiently. He is brilliant! So much better than the dumb alternator……

Good luck
Greg

[HarrisonM]

NYSail:

Any chance you could share "Rod (mainsail)" contact info?

Harrison
harrison.midkiff@gmail.com
Tarpons Springs, Florida