Alternator options???

[Mojo_Scott]

On a sailboat with the house bank and an engine bank,Why spend $1200+ on a high amp Balmar Alternator when something like this is available?


https://www.dbelectrical.com/product...BoCDpMQAvD_BwE

[Paul L]

There are lots of good alternator alternatives to Balmar, but they aren't painted white

[Jammer]

Originally Posted by Mojo_Scott

On a sailboat with the house bank and an engine bank,Why spend $1200+ on a high amp Balmar Alternator when something like this is available?


https://www.dbelectrical.com/product...BoCDpMQAvD_BwE

Well, let's see.

It doesn't have an isolated negative, so if that matters to you (and it should), then you've got a problem.

It's an internally regulated, one-wire alternator, which means you give up any ability to control output in a nuanced way. There's no voltage sense line, no battery temperature probe, no means of reducing output when full engine power is needed for propulsion or when the engine is cold.

It's based on the GM CS130 alternator, a smaller framed and older design compared to the GM AD244 upon which the Balmar alternators are based. They run hotter, produce less output, etc.

There are other sources for overwound AD244 alternators. Most are not marinized. If you can live without marine-specific features like the isolated negative, well, maybe those other suppliers are right for you. In shopping for alternators in particular I have not found that the prices are that much different -- the places that sell to the 4x4 and ambulance and street rod and tow truck markets all charge crazy high prices just like the marine guys.

[rom]

Originally Posted by Paul L

There are lots of good alternator alternatives to Balmar, but they aren't painted white

I am sure there are but not so many come with a 3.15" saddle mount for yanmar owners.

Or is there an easy way to fit a J180 (4") mount on a yanmar ?

[Mojo_Scott]

Jammers response is the direction of info I was looking for - thank you. I’m trying to understand the differences and trying to justify the price differences.

Why is the isolated negative important? Isn’t the engine grounded through the starter and thereby the whole system anyway? The standard “Perko” battery switch only isolates the positive side of the systems.

I understand the need for an external regulator, and in figured with a little searching I could find a similar AD244 based externally regulated high output alternator that was similarly priced.

Fabricating a mounting option for our engine is not the problem. Finding a sensible alternative to what looks like a grossly overpriced marine product is my goal.

[rom]

Originally Posted by Mojo_Scott

Jammers response is the direction of info I was looking for - thank you. I’m trying to understand the differences and trying to justify the price differences.

Why is the isolated negative important? Isn’t the engine grounded through the starter and thereby the whole system anyway? The standard “Perko” battery switch only isolates the positive side of the systems.

I understand the need for an external regulator, and in figured with a little searching I could find a similar AD244 based externally regulated high output alternator that was similarly priced.

Fabricating a mounting option for our engine is not the problem. Finding a sensible alternative to what looks like a grossly overpriced marine product is my goal.

I'd be interested in how you intend to proceed with the mount if you care to share.

Did you have a look at alternatorparts ?
https://alternatorparts.com/ad230-ad...ternators.html
They also sell external rectifiers for a fraction of the price some marine guy sells them ... And simple external regulators that would work for me, maybe not for you (not 3-stage etc ...)

[Mojo_Scott]

I’m considering running two Alternators on my Westerbeke 21. Leave the stock alternator to charge and maintain the starting bank and add a high output externally regulated alternator for the house bank (4- T145’s)

I have plenty of room above the motor to fabricate a sturdy mount for a second alternator, but I would have to source dual groove pulleys.

[Sailmonkey]

I would be awfully surprised if that alternator can support 150 amps of continuous output without burning out a diode or winding.

[kenbo]

Originally Posted by Sailmonkey

I would be awfully surprised if that alternator can support 150 amps of continuous output without burning out a diode or winding.

The cs130 was notorious for burning up diodes.

[Stu Jackson]

Originally Posted by Mojo_Scott

I’m considering running two Alternators on my Westerbeke 21. Leave the stock alternator to charge and maintain the starting bank and add a high output externally regulated alternator for the house bank (4- T145’s)

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Skippers have been working on alternator charging systems for many, many years. The consensus is that a starting battery needs very, very little "re-charge" after starting small diesel engines. It uses a few ahs at most: high current, tiny amount of time. Your start bank wont need much if anything, and your original alternator would be spinning, not needing to do anything electrically.

Rather than go to the expense (or whatever other work, and what you choose to call it) of a second alternator, why not do what most have done: add a VSR/ACR/combiner, and route the alternator output to the house bank.

Alternator Sources by Maine Sail (Reply #16)
Additional New Alternator Source & Maine Sail's Analysis of Alt. Sources

[Colin A]

Like others have said there are other makers out there. But once you get into external regulation etc the price difference becomes less. I know several people have had good luck using alternators of commercial buses and school buses. (dock head for instance on this forum) I recently saw an install of one in an old trawler. It put out plenty of amps and had a remote voltage sense wire to the battery. In this case the owner just let it put our 14.1 volts (via the internal reg) to the batt as he has solar that is his main charge source.

[Paul L]

Originally Posted by Sailmonkey

I would be awfully surprised if that alternator can support 150 amps of continuous output without burning out a diode or winding.

You are certainly right on this. Of course a small frame Balmar advertised as 120 amps can't deliver 120 amps anywhere near continuously either.

[Sailmonkey]

Originally Posted by Paul L

You are certainly right on this. Of course a small frame Balmar advertised as 120 amps can't deliver 120 amps anywhere near continuously either.

True, but it will withstand much higher temps with greater sustained current than a 200amp automotive alternator.

[Paul L]

Originally Posted by Sailmonkey

True, but it will withstand much higher temps with greater sustained current than a 200amp automotive alternator.

So why not market it at its honest output?

[Cheechako]

Something like that can be easily converted to a externally regulated type. Or you can just buy a Leece Neville or big frame Delco that is already converted. People have used and proven those for decades. You dont need to spend $1200 on an alternator for sure.
Also, the bottom line is most battery banks cant take a ton of amps for very long anyway. The battery is the limiting part not the alternator. For instance, a 100-125 amp alternator will run for maybe 15-20 minutes at 80-100 amp output then back off quickly.