Good grief, it never ends. Alternator upgrade needed.

[Singularity]

Originally Posted by john61ct

Again you will buy absolutely **nothing** by increasing amps output with that FLA bank, they just do not **accept** more than .12-.16C, and even that for only a very short time, quickly scale down for the next 5-6 hours at least.

Don't throw money away on a fantasy

My impression looking at his boat (nice design, incidentally) and the fact that he's in a place where the sun don't shine so much is that sooner or later at minimum he's going to desire a larger bank and/or more utility (e.g. electric galley). Sometimes spending an extra $4-500 (pulleys/bracket) gives you a lot more options such that you actually enjoy the thing more. Why spend $100-500+ on a smaller alternator now when a more capable alternator in the future will cost an additional $100-500+ plus some new thick wires at that point.

Not saying I'm correct, just ideas to chew on. Otherwise agree with Jim's logic that you've articulated previously.

To the OP...what is the chance that you're going to want to do extended cruising in the future? Liveaboard? Convert your galley to electric? Planning on solar? A generator?

[john61ct]

As stated, even doubling the bank will still not be getting the 70A alt close to fully utilized.

spend that money on solar

[Jim Cate]

spend that money on solar

Yes, exactly, the money you save by buying the much cheaper GM 140 amp alternator.

Jim

[john61ct]

Sure, if that's acceptable to OP

[NYSail]

I upgraded to a balmar 150 amp mc614 reg and serpentine belt. What a great upgrade..... charges bank beautifully? Derated alt..... money well spent. Check out Maine sails site..... I bought entire package from him and got a great price with great advice.

Good luck!

[Bill O]

Evan,
Not sure what you have available where you are located, but the easiest thing to do if take your old alternator to a gen/alternator/starter shop if you have one near you. They can most likely fix/rebuild your old one for a few dollars.

The older Perkins 4.108 and 4.236 motors came stock with Delco Remy 10SI alternators with internal regulators. These are very rugged alts and available world wide. There were 10SI alts with 37 amp, 42 amp, 55 amp, 61 amp and 63 amp ratings.

A relatively newer DR alternator is the 12SI with the same casing size, but higher amp output and better cooling capacity over the 10SI. The 12SI were built with 56 amp, 66 amp, 78 amp and 94 amp max. output ratings.
Without knowing what you have for electrical needs on your boat, IMO you'd be fine with the 10SI 63 amp alternator.

As mentioned by others, invest in solar instead of the expensive Balmar system. If you keep your electrical consumption to a modest level (and sufficent solar) then you don't need to depend on your propulsion motor to be the sole source of electrical production.

We only run our Perkins 4.236 to get in out of anchorages or windless days and our DR ~80 amp alt with internal regulator works fine to top off the bats. We are modest electrical users and the solar provides most of our charging.

If you can't fix your old alternator, PM me and I'll send you a list of replacement alternators from the automotive stores. For <$100 you can get a new 12SI 78 amp alternator to install (if nothing else would be a good spare).


Bill O.

[sailandbail]

Originally Posted by rbk

oh check out craigslist southeast alaksa, guy has x2 120 or 150 balmars and regulator(s) for sale $400 for each setup, not that old.

Wow, that seems like a really crazy deal. I'm definitely going to inquire. I really appreciate you sending that to me. He says they work well and I suppose I'd just have to cross my fingers, otherwise take them to someone local to have them serviced?

Thanks again.

[mark maulden]

I have a single 2” foot 80a Balmar i will sell ya. Would need a regulator. I’m just down the road from you. BTW, I know the former owners of Seabird

[artisanmach]

I would go with a GM 10-DN this is the tried and tested externally regulated version that has been around for 50+ years. it is easy to rebuild, parts are easy to get. I would still use a Balmar regulator. Quick Start
https://alternatorparts.com/10dn-alt...-and-kits.html makes a much-improved stator they come in 63A 105A and 140A I have used them in service trucks, my motorhome, and my boat. as with any alternator... heat is the enemy. I would duct cooling air. on the 4108 I would also purchase the serpentine belt setup. side note the 4108 has only 3 main bearings and cannot deal with too much side load, you can't tighten the belt so much that it deflects and breaks the end of the crank.

[sailandbail]

Originally Posted by Singularity

My impression looking at his boat (nice design, incidentally) and the fact that he's in a place where the sun don't shine so much is that sooner or later at minimum he's going to desire a larger bank and/or more utility (e.g. electric galley). Sometimes spending an extra $4-500 (pulleys/bracket) gives you a lot more options such that you actually enjoy the thing more. Why spend $100-500+ on a smaller alternator now when a more capable alternator in the future will cost an additional $100-500+ plus some new thick wires at that point.

Not saying I'm correct, just ideas to chew on. Otherwise agree with Jim's logic that you've articulated previously.

To the OP...what is the chance that you're going to want to do extended cruising in the future? Liveaboard? Convert your galley to electric? Planning on solar? A generator?

I really enjoy thinking of different ways to approach this and I appreciate you guys taking the time to help. The chances of me doing extended cruising in the future are 100% provided I don't make some massive mistake and sink the boat, or completely lose my mind in the process of getting her set up.

I already live aboard and 90% of my evenings are inside of the marina plugged into shore power while I try to get everything sorted out.

I'm not sure what you mean by converting my galley to electric?

I run a Webasto heater when it's cold, which is mighty efficient with fuel, but not so efficient with power because fans are powered at every output (in the heads, aft cabin, galley, v-berth) and it's currently set up so that you can't isolate anything. It's either ON or OFF, which seems wasteful.

I would love to add solar, the sooner the better, even though we don't have a great deal of sunshine up in the Pacific Northwest.

A generator sounds like it would be a real treat to have, but the cost of that scared me off, at least for now.


Thanks again for the input!

[sailandbail]

Originally Posted by mark maulden

I have a single 2” foot 80a Balmar i will sell ya. Would need a regulator. I’m just down the road from you. BTW, I know the former owners of Seabird

Hey Mark, let's get in touch! Can you shoot me a text? Thanks!

Evan
206-696-0787

[techmans]

For the time being you can cheaply fix the existing alternator of which most likely the brushes are worn.Either put in new brushes or square off the existing stubs and stack an extensions on them.You can shape the extensions from any brush material at hand ( discarded vacuum,power tool or what have you)

[hellosailor]

I'd be skeptical about a 12SI new for $100. If anything it will be a repainted used or rebuilt part, not Delco, not new.

Real "new" alternators tend to be $400-$600 parts from prime makers. And after the production run, what you get as new is really "remanufactured" which means a defective alternator is stripped down to the frame, and each part, each bearing, everything, is actually tested to make sure it is within factory original spec before the alternator is rewound and "made" again.

That's in contrast to "rebuilt" which just means "we fixed whatever was broke, we don't know about the rest, it works now".

With a coat of shiny paint (which can cause heat build up and kill the diodes) they all look new. Sometimes you can get a suitable (commercial, or old Cadillac/Lincoln stock) alternator off a low-mileage wreck for 1/4 the price of a rebuilt one, and it will actually last longer. Cheap enough to have a spare.

The OP's bank would be...230A @ 12v ? and wet lead is generally suggested to be charged at 20% of the C rating, which would be 45A charging in this case for five hours. (OK, six to overcome losses but more like 2 if they were only pulled down "reasonably" not deeply discharged).

So the 70A alternator probably could feed them happily. I think the questions are what is the continuous duty rating on that alternator, and how good is the airflow, the cooling in the installation, because THAT is going to clamp down the output--or kill the alternator.

A ribbed belt (serpentine or not, most folks confuse the two) is the modern better way to go. Simply finding the correct V-belt profile and length is an exercise these days. But if the OP is certain he won't be doubling the bank size...I think I'd just size up to an 80 or 90A rated alternator, for longevity, and make sure the regulator, sense lead, and everything else were also up to date. On 40 year old systems they often used a "fusible link wire" coming out of the alternator, instead of a fuse block. Today, those wires (even when covered in a fiberglass tube) are referred to as fire hazards.

[George DuBose]

I have had bad luck with my Balmar 100 amp alternator. It went south after a long motor around Denmark last summer. I called Balmar and they told me that the Balmar smart voltage regulator probably got too hod and components on the circuit board had their solder failing from the heat.

My smart voltage regulator is OUTSIDE the engine compartment. $300 bucks later, they repaired my two year old alternator. I really didn't get the impression that the factory service was very good, certainly not good at communication.

What this experience taught me is that it is important to keep the temperature as low as possible in the engine/battery compartments.

You can go as high as 100 amps with a single belt.

On the other hand, I never had any trouble with the stock Yanmar (Hitachi?) alternator, it was rated at 35 amps and I wanted to charge my battery bank with more oomph. I now carry the Yanmar alternator in my onboard parts box.

[boatpoker]

Delco Remy 100amp from a truck alternator place have an external regulator fitted ... about $150 in my neck of the woods and you do not need a serpentine system on that engine. They're just trying to sell you stuff.

Been running cheap truck alternators for years, no problems. Hell buy two and still save a small fortune.