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Old 07-06-2009, 20:29   #61
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"Rick et al was very much right, the output of the Hitachi alternators is definately sub-optimal. "
I don't read his message as saying that at all. Just that with an external regulator, they can be operated at 113% of capacity, which presumably will shorten their life or reduce the safety margin, but to what may be an acceptable point in marine use. Alternators on a sailboat, after all, don't need to run as much as they do in cars where 100,000 miles (2000 hours) would be considered a cheap part and 4-5000 hours common for brand names. Assuming you take the number at face value.

It can be difficult to get technical specs from Hitachi, real specs for output-vs-rpm and so on, that US makers openly publish for their alternators. Without the specs, it becomes impossible to make the optimal use of any alternator.
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Old 07-06-2009, 20:32   #62
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the three happiest days in a sailor's life:

1. the day you purchase the boat
2. the day you replace the Hitachi alternator with a Balmar.
3. the day you sell the boat.
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Old 08-06-2009, 04:23   #63
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Originally Posted by hellosailor View Post
... It can be difficult to get technical specs from Hitachi, real specs for output-vs-rpm and so on, that US makers openly publish for their alternators. Without the specs, it becomes impossible to make the optimal use of any alternator.
Alternators are typically (cold) rated at 5000 RPM alternator speed.

Performance curves for the Hitachi 60 & 80 A Alternators start on page 12 of the Yanmar Marine Installation Manual (3YM30).

Goto ➥ http://psyberspace.com.au/yanmar/installationmanual.pdf
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Old 08-06-2009, 06:59   #64
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In your analysis of the effectiveness of HO alternators, you are assuming that you cranks up the main engine just to generate power. Maybe that's your situation, but it is unusual, so I don't think that's a fair assumption for most cases. The great thing about HO alternators is that you make a bunch of electrical power as a by-product of propulsion. So if you motor even a little every day or two, you've almost made your power budget at no cost whatsoever.

And that's why alternators are most sailors' primary power sources.

We have a 175 amp x 24v high output alternator charging the house bank, and a smaller separate alternator charging the engine start batteries. Besides that, we have a 5.5kW diesel genset. Life is good. We rarely use the genset because we don't have air conditioning and we rarely hang out on the hook for more than a day or two (but it is really great knowing the genset is there). When coastal cruising, we usually move at least every other day, and even in good sailing conditions we'll run the main engine for an hour or so every day, when you add up leaving the old anchorage and getting into the new one -- putting a substantial charge on for free.

Even crossing the Atlantic (I'm hypothesizing here, not having ever done it), I would think that you would do a certain amount of motoring, whereupon you'd get a rapid and free charge of your battery bank.

Wind and/or solar as a backup is a great idea, of course, no matter how many diesel-powered energy sources you have. As someone said -- diesel, wind, water, solar, nuclear, fuel cell -- whatever; the more diversity, the better.

For your situation -- where you expect to spend days or weeks on end without moving -- the needs are different. I guess wind generation looks pretty good from that perspective. But you will want to have a decent alternator, I would think.
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Old 08-06-2009, 07:24   #65
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The bad: The internal regulators have a negative temperature coefficient that tapers off the output current well before any excessive temperature build-up occurs internally. The regulator actually attempts to control the internal ac, not the external dc output. As a result, the greater the dc output current the lower the dc output voltage due to the diode drops not being compensated for. The overall net effect is a very conservative operation which works fine to recharge a start battery and maintain the engine "electrics" during operation. Performance in recharging deeply discharged batteries is not merely poor, it is unacceptable.
I interpreted that as suboptimal. Okay, lets just say "unacceptable"

But in any case, my point is I will not use engine driven alternators as a primary, or even secondary source of energy for the house battery bank. In my mind there are far superior and cost effective methods of generating power. With three phase regulation, I don't even think it is practical to use them to bring my batteries (Lead/Acid technology) back up to %100. Bulk phase, they can be unbeatable, acceptance phase ? float, definately not . The alternators are expensive, the regulators are expensive, the depreciation on engines are expensive, maintenance is expensive, fuel is getting more and more expensive. Then there are the non-monetary considerations. My engines are noisy and embarrassing to run when I am in an otherwise quiet anchorage, I have to change the oil, I have to change impellers, change filters, clean strainers, find fuel, strain fuel... And no, I would not do without them!

On solar, as an example and in comparison, the panels are expensive, the MPPT controller is expensive, the depreciation is inexpensive, maintenance is inexpensive, fuel is free. Non-monetary - Ahhhhh.... And all that environmental stuff everybody keeps debating.

For bulk phase charging, a portable generator (a purpose built genset could provide the same utility) has been an outstanding solution for me. I use the portable for bulk phase charging, then use wind and solar for acceptance and float to some degree.

This multi source power approach has worked VERY well, so far. My batteries are something over 6 years old right now. A good 2 years of that time being spent cruising. (yes, they will be replaced shortly, as probably as soon as I find out some details on the Surrette - AGMs.)

Now, if I already had and HO alternator, I'd not throw it out. But, I'd still be considering solar or wind as a way of getting the bank back up to 100% as often as I could.

These thoughts are also with cruising in mind. There is NO way I can beat the cost and convenience of plugging into shore power! If I were only going out for a weekend or only doing 1 week on the hook in a year. Shore power and a 1kw portable I could use at home would be my primary sources.

Fair winds!

Keith
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Old 08-06-2009, 08:40   #66
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In your analysis of the effectiveness of HO alternators, you are assuming that you cranks up the main engine just to generate power. Maybe that's your situation, but it is unusual, so I don't think that's a fair assumption for most cases. The great thing about HO alternators is that you make a bunch of electrical power as a by-product of propulsion. So if you motor even a little every day or two, you've almost made your power budget at no cost whatsoever.

And that's why alternators are most sailors' primary power sources.
Yes, I am pretty much assuming that you are primarily running the engines to recharge the batteries. What we did was find great anchorages, spend at least a couple of days, often times more, then move to a new spot and repeat! We move a lot less than we were at anchor. When we did move, while in the states, we would do an awful lot of motor sailing. Much more than I thought. Often times up to 8 hours a day. So much so that we adopted only running one engine. In the Islands, we sailed often. While we were sailing, we got MUCH more utility out of the wind generator! It was enough to power our autopilot, plus bring the batteries back up. But, since this was such a proportionally smaller part of our cruising, I can't say it justified the headache of the wind generator. If I were ocean crossing however, I'd not do so without a wind generator. Many people have a had a different experience with wind as they go further down south in the Caribbean. They say their anchorages were usually windy, and they got lots of power from the generators.

Now, if you're only running your engine for short periods of time. I have to agree, HO may make a lot of sense. But, when we ran our engines for motor sailing, we ran them for extended periods of time. We found, even with the lower output level, we got our batteries to 100%. I even found I motor sailed more often than REALLY necessary, just as an excuse to top up the batteries. Most discussion I have observed seem to mention running the engine as a central part of a power management scheme. They run to generate power and do other things since they have excess. Some folks do use engines as a core portion of their refrigeration scheme. If that is the case, HO is far more compelling. Kollmann has suggested that thin evaporator plates are the most efficient form of refrigeration you can use. That is consistent with what I have found, but once again, if that's not what you have, I am all for optimizing your in place systems.

I certainly don't pretend to know everyones power management routine, but it is definitely not unusual for people (in the US, Canada and Caribbean waters) to fire up the engine just to top off the batteries.

When I started redesigning my boats systems, I did a lot of reading. Magazines, Nigel, here, SCCA, Lats and Atts, etc. I attended a lot of boat shows (Annapolis, Miami) I presumed I was going to go HO. I started designing the system. Okay, I have two engines, back then I thought I'd run both when motoring. I thought I'd have to synchronize the output of the alternators. I thought I'd have to get two HO systems because I want to balance the engine usage hours. I thought I'd have to get the two belt alternators to maximize the power, I thought I have to get a bracket fabricated because so many folks were having issues with the brackets failing. I thought I'd have to get a new pulley for the engine because of two belt issue. I thought I'd have to get bigger fuel tanks to support longer run times on my engines. I thought I have to optimize the battery bank to accept the power available from the HO alternators. I thought (Still have the holding plates!) I'd have to get an engine driven and AC refrigeration system because I was running the engines. I thought my engine would power my water maker... But, when I started adding up the cost, I was shocked
When I started talking with people who were cruising, had been cruising, it was eye opening. As I said in an earlier post, I ran into so many folks that had these little, toy, GASOLINE generators, how could they work???? Well after using one for three years, my conclusions is, WOW, they do! Just as amazing, I haven't burned my boat down to the waterline, yet! (Still keep an extinguisher handy though). I remember discussions with Sean about building a diesel generator...

I whole heartidly believe the dialog is the benefit of forums. So folks have access to theory and practice and can consider solutions that work for them in their particular circumstances. Definately not any single solutions work for everyone, in all circumstances, heck, I even know some people that still sail in monohulls! (Okay, so almost all my friends, Greg and Bil, we are so alone! Jeez, I even have cruiser friends that do trawlers and power boats ) I also think it helps to see what has happened as the test of time progresses. I try to periodically give updates on some of the things that I thought would work and have, and some of the things I thought would work and haven't. I even try to correct myself when I have been wrong (Sorry Gord, you were right about the no wind anchorage, but the wind generator noise still doesn't bother me )

So, I think we do a great service by presenting many aspects of a power management scheme. So, If you'll just remove all your HO alternators and send them to me, I'll properly dispose of them! (Believe me, if someone gave me a HO alternator, in good shape, I'd probably find a way of making use out of it. But $500+, Give me another solar panel every time )
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Old 08-06-2009, 09:36   #67
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Stryg, I would only disagree in that the real cost of solar panels versus anything else is subject to a lot of variation. When I ran the numbers for solar against engine powered alternator, IIRC solar was 5x more expensive no matter how you sliced it.

But when you run the numbers for solar against a remote installation, i.e. a military forward base where the real cost of genset fuel may be $40-100 per gallon "delivered"...solar is a lot cheaper, sure. Your mileage may vary.

Little Honda gensets still have a sweet spot in the grand scheme of things, don't they?<G>
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Old 08-06-2009, 09:41   #68
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Gord, thanks for digging that up. It isn't the same Hitachi/60A that I've been looking for (I don't think, I'll have to find numbers again) but Hitachi likes to say all that information is proprietary to the customer (i.e. Yanmar) and won't release it to the public. That you found it in an Aussie site should tell you how unavailable it generally is, just try to find it by a web search!

Looks like a nice alternator with an exceptional speed range (up to 18k rpm?!) and not their typical product.
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Old 08-06-2009, 10:31   #69
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Hellosailor;

I don't know, I ran some number a while back on solar verse engine power generation. It is in a post on the forum. The rough approximation was I burn say .5 gallons an hour. I run my engines 2 hours a day to put power back into the batteries. I was in the Bahamas at the time, so fuel was costing me $5 per gallon. Since I was on my boat full time, I would have to spend $150 per month for power. In one year that's $1800. Now, we can play with the numbers a whole lot, for instance, drop the price down to $3 per gallon, that's $90 per month, $1080 per year. The presumption being, if you're cruising full time, for an extended period of time, the ROI on panels gets awfully short.

We could get into depreciation, maintenance, opportunity cost and a whole host of other things. We can talk about the relative cost associated with installing anything else, if it is over and above what you already have. We can even say solar doesn't provide 100% of our power needs (Although Bil from Makai I believe suggested otherwise) But, I believe the presumption still holds. Now, I'd absolutely not argue the cost effectiveness of solar in relationship to shore power, or not using anything. Saving is always going to trump efficiency, and paying $.12 per kilowatt hour it is certainly going to take a LONG time to displace the cost associated with installing solar. But against fossil fuels??? I'd have to see some mock numbers.

Yeah, the Honda's are sweet (Full discloser, I have a Kipor. Too cheap to pay for the Honda. And I thought after a year I was just going to throw the thing out because it was completely unsuitable for the use I was putting it.)
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Old 08-06-2009, 10:33   #70
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Yeah, I was jealous, that is the same info in my installation manual that I had to pay something like $125.
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Old 08-06-2009, 11:25   #71
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2 hours a day? To get how many AH out of what size alternator(s)? And replaced by how many watts of rated panels? (Assuming also that the panels are warranteed for marine use, apparently there have been enough failures that many are no longer warranteed at all for use afloat, a 25-year life can't be expected.) A propulsion diesel makes a lousy genset, I agree, but that's of course assuming you're not also using it for anything else at the time.
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Old 08-06-2009, 13:16   #72
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2 hours a day is very light usage, but to increase the number of hours above that makes the cost even higher. I was assuming perfect conversion of an 80 amp hour Balmar solution that runs about $700 with external regulator. So, to produce 160 amp hours a day would cost $x.

We do however know that even if we are able to present 160 amps to the battery, it is only going to accept 160 * (some efficiency factory, say 94%) But, that just makes the model more complex and I think mostly contribute to either getting a larger solution (higher cost) or increasing the run cost due to additional hours. Both these would result in a quicker cost recovery in the model.

So, lets propose an HO solution and assumption and let's plug in a few numbers. My assumption, is continuous cruising (we're on board 24 x 7 ) with no access to shore power. Let's assume our on-board system usage requires us to present 240 amp hours to the batteries over a twenty-four hour period.

What HO system, and what run cost would you think?
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Old 08-06-2009, 14:53   #73
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"So, to produce 160 amp hours a day would cost $x. " OK, let's say diesel is $5/gallon since it will be there again. That's 160 AH at 14.4 volts, or 2304 watthours--which is the better way to compare against solar panels, which are rated in watts and typically produce 4-6 the watt rating in real life under optimum circumstances, i.e. a 100W solar panel can be expected to produce about 500 watthours of power per day.

And we can ignore inefficiencies in both, at least to ballpark. If the Balmar system is using a pulse width output alternator (like the old Delcotrons!) then the efficiency could be very much the same as an MPPT controller using PWM. Depends on the gizmos, not the raw source, and the sorbancy of the battery bank.

So...To match two hours ($10 of fuel) on the 80A alternator, you've got to install some 400 watts of solar panels. Still a bit unfair, as the odds are your engine is able to put out 15-20hp while consuming that same fuel, and a larger alternator (or a dual set) would double your power output and cut your cost in half.

What's that 400W solar panel set going to cost, and do you have room to install it? And, a Solar Stik or other mount to optimize the output by letting it track the sun all day?<G>

Two hours may also be arbitrary. Size the battery bank, remember you're going ot half-cycle it, and AGMs can be half-cycled in 2 hours, so that's a match if the power figures match. Or...if the bank isn't 50% discharged EVERY day, it might only need an hour or a half hour, even without hanging more alternator on the engine.

I've seen a smaller installation (MD7A with a 70A Delco pushing two Group31 wet calls, IIRC) literally cut the charging time IN HALF after we resized the alternator pulley, so that the engine could run the alternator at full output at normal cruising speed. The original installation was a kludge using the original pulley from a Marchal alternator that someone had just moved to the Delco during a "get it home" repair that stayed in place for too many years.<G>

Just gotta bump out the walls of the engine bay to allow for some proper alternator installation, right?<G>
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Old 08-06-2009, 16:29   #74
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So, I could install 3 170 watt panel, that would give me 510 watts. That's what I'd expect to install to generate the needed 240 amps a day. Most days, we'd be way over, some days under...

We can get the panels for $700 each. ( BP Solar 175B, 175 Watt Solar Panel - Home Solar Panels - Solar Power Panels ) Hmmm... they are 175s so that's 525 watts.... I am assuming there is $70 or so each for shipping.

Get an outback MPPT controller. I am partial to Outback FM 60. (Outback FM-60, 60 Amp MPPT Charge Controller :: OutBack Charge Controllers :: OutBack Power Systems :: Alter Systems On-line Shop - Go Green for Life™ ::) Another $600.

Add another boat buck for installation and misc. Total $3700.

Now, if we are indeed spending $10 on fuel a day for the two hours of run time. We recoup our cost in 1 year and 5 days. Isn't that neat! We haven't even looked at the cost displacement associated with not buying the HO alternators, or engine depreciation, or increased maintenance time, or increased maintenance cost, or installation.... or Tax credits! Can we say cha-ching! (yes, boats are eligible for the energy credits, just trying to figure out if I can recover part of the cost of a fixed Bimini as part of it too!)

Space. hmmm.... buy a catamaran... just joking!!! I am assuming in the $1k it is going to give you some latitude in creating a mounting solution. It cost me about $125 to mount two panels. I really could have mounted 3 if I'd wanted to go with a more permanent solution... but that's another thread.

The unfair part is that I am assuming you don't have to run your engine for other things. The other point is you don't have shore power available. As I suggested at $1.50 per day for shore power, its going to take me a long time to recoup $3,700. (hmmm... something like 5.4 years, that's not as bad as I thought it would be!) I designed my boat systems so I wouldn't have to run the engine for other things. I don't have an engine compressor for refrigeration. My water maker works from 12 volt DC. I have a dive compressor that runs from gas. I don't use air conditioning when I am not in a marina. My stove works from propane. My engines can put out a LOT more energy than I could use. I have two engines and could theoretically put on 4 HO alternators on them. But, that would just generate a lot more energy that I'd have no way of storing given most current battery technology.

The two hours I use is because that's what I hear in most discussions. Truth was, it was taking me 4 hours to bring my batteries back up to 85% after I broke my wind generator blade, and didn't have the portable generator.

I used the BP 170 model because I have a couple of year worth of data on that. I consistently average 80 amp/hours a day from the thing. It's absolutely amazing with the MPPT. Even more amazing to me is that it generates output even on cloudy days. Not as good as a sunny day, buy I still see 1 or 2 amps when it is quite overcast. 3 gives you enough excess capacity that you could cover the underage for the cloudy days, or run other loads with the excess capacity. But.... All that is not germane to the ROI discussion based-on variable cost.

I don't do any panel adjustment, everyone that I have had discussions with say it's not worth it. My 80 amps is on a fixed installation. Adjusting them to track the sun would be a waste of good drinkin time! ;o

I know all this seems so, theoretical, but it was driven by a real world problem. I couldn't understand why I was spending so much money on diesel, when I was spending so little time moving. I got 50 gallons, it was just around $240 and I was doing it every month. That's when I got the portable generator, that's when I noticed I really needed to get my wind generator working again! When I really wish I'd bought more panels!
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Old 08-06-2009, 17:15   #75
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along the way you will be wanting a good alternator. High output means a lot of different things, but I would strongly advise 75-100 amps. I had 100 amp alternator with a 4 winds generator also on one boat. even with the wind blowing pretty well each day, on the second or third day I would need to run the engine to keep up with the fridge and ham radio. In most anchorages you cant hear your neighbors engine running. You can sure hear those annoying wind gens....
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