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Old 18-07-2014, 07:53   #61
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Re: Solar and AGM'S

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Originally Posted by tedsherrin View Post
Well, having read the link I can see there is quite the stirling / Balmar camps.
We have both on board - an externally regulated Balmar alternator and a stock internally regulated OEM alternator used with a Sterling device - so have the experience to speak from both camps!

Both do what they say they do - there are no bodges or snake oil. They fit different needs in time and equipment.

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Old 18-07-2014, 08:21   #62
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Re: Solar and AGM'S

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Originally Posted by colemj View Post
The typical cruiser is better off adding more solar than replacing a decent internally-regulated alternator like your stock 90A. Use the stock alternator to quickly charge the initial part of bulk in the morning if needed and let the solar carry to full charge through the afternoon.

Mark
+1, why not just keep the 80 watt solars and add the new 120's. Pivoting mounts work far better down here in Tas to milk more morning and afternoon sun, hinge them off the stern rails.

The whole idea of a sailing boat is not to be shackled to having to run the engine. Nothing beats a silent passage, and I can think of nothing worse than having to run an engine just to keep my fridge cold. I'd far rather drink warm beer!

Put the effort into reducing your energy needs, sort out that trim tab windvane, simplify your boat and I think you will enjoy being aboard much more. I look forward to seeing you out sometime, but not if you are running that damn engine at anchor in wineglass or the duckpond to charge your batteries.
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Old 18-07-2014, 16:10   #63
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Re: Solar and AGM'S

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Originally Posted by colemj View Post
...No one type of LA battery needs higher charging current than any other type...
I'm afraid you are wrong again. Please read the 37 page Lifeline manual. They need a minimum charge current of 20%C. They don't say why, but I believe it is to do with burning off contamination that can build up on the separator plates.
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Old 18-07-2014, 16:24   #64
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Re: Solar and AGM'S

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Originally Posted by sailinglegend View Post
I'm afraid you are wrong again. Please read the 37 page Lifeline manual. They need a minimum charge current of 20%C. They don't say why, but I believe it is to do with burning off contamination that can build up on the separator plates.
The engineers at both Odyssey and Lifeline insist that higher charge currents will lead to longer life. Odyssey is slightly more adamant about this than Lifeline but both are on the same page. The biggest problem is that neither company is willing to quantify how much shorter life you will get at low "C" rates just to say that low "C" rates will impact cycle life.


Odyssey Battery:
"When using a charger with the IUU profile, we suggest the following ratings for your ODYSSEY battery. Note the charger current in the bulk charge mode must be 0.4C 10 or more."
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Old 18-07-2014, 16:53   #65
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Re: Solar and AGM'S

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Originally Posted by sailinglegend View Post
I'm afraid you are wrong again. Please read the 37 page Lifeline manual. They need a minimum charge current of 20%C. They don't say why, but I believe it is to do with burning off contamination that can build up on the separator plates.
If your definition of wrong is when you continually mis-comprehend what you are reading and I correct that, then yes, I am wrong again.

Page 37 in the Lifeline manual I have is a graph of charge voltage vs. temperature, but here is what it says about charging current in the text: (arrgh, the file is protected and won't let me copy/paste from it - I am not typing it in)

So let me instead summarize what you have been misinterpreting.

1. (this is a direct quote from the text) "Charging Lifeline AGM batteries is a matter of replacing the energy removed during discharge plus a little extra to make up for charging inefficiency".

2. Lifeline states that their batteries should be fully charged regularly or they will suffer shorter lives.

3. The charging current during bulk charging should be as high as possible because that means a faster recharge time. They mention that at 0.25C it will take 4hrs to recharge and at 0.1C it will take 7hrs.

4. If full recharge is not achieved because the charging time is too slow, then the battery SOC will "gradually walk-down" as it is cycled continually. This will lead to shorter battery life. Again, Lifeline recommends that their batteries be regularly brought to full charge - this is different from FLA's.

5. For repetitive cycling below 50% DOD (this is deep discharging and most attempt to avoid it), they recommend an output current of at least 0.2C or "the cycle life of the battery may be negatively affected". If this is not practical, they recommend a low current be applied for a long time after the end of the absorption stage.

I think you are caught on #5, which again is for those batteries routinely discharged deeply.

The recommendation here has nothing to do with voodoo like "burning off contamination" (why do you make things up even when you are admitting you don't understand them?). It has everything to do with Lifeline recognizing that AGM's are uniquely fragile in the LA world when it comes to deep discharges without full recharges - they are telling you to fully recharge them.

So they recommend either supplying a large current so that the time it takes to recharge them is shorter (remember, it is going to take at least 4-7hrs to do this, and it needs to be done regularly - like almost daily), OR supplying what amounts to an equalization charge by putting the charger in a constant current mode for one hour after absorption.

In case you are confused, a constant current will increase the voltage on a battery. If done like Lifeline recommends, the battery voltage will climb to over 15V over that one hour. If left on for more than that hour, you will damage the battery.

Look, I am really not interested in debating this stuff with you. I will post what I do and leave it to others to consider. They can differentiate between correct and incorrect knowledge.

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Old 18-07-2014, 16:57   #66
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Re: Solar and AGM'S

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Originally Posted by Snowpetrel View Post
+1, why not just keep the 80 watt solars and add the new 120's. Pivoting mounts work far better down here in Tas to milk more morning and afternoon sun, hinge them off the stern rails.

The whole idea of a sailing boat is not to be shackled to having to run the engine. Nothing beats a silent passage, and I can think of nothing worse than having to run an engine just to keep my fridge cold. I'd far rather drink warm beer!

Put the effort into reducing your energy needs, sort out that trim tab windvane, simplify your boat and I think you will enjoy being aboard much more. I look forward to seeing you out sometime, but not if you are running that damn engine at anchor in wineglass or the duckpond to charge your batteries.
I'm completely with you Snowpetrel, up until now I have not had to run the engine specifically to charge the wet cell bank of 520ah. Just the running of the engine to move from the pick and in entering somewhere was usually enough. I would hope that with going back to two solar panels I'm going to have enough. All this discussion of regulators has been quite confusing.

Prior to me buying a boat I hired a very expensive dry hire yacht in the Whitsundays to see if I and the family liked it. About the worst thing about that trip was that we had to run the engine at anchor at 2O00 revs for two hours before we settled down for the night. And despite it being a relatively new boat it was LOUD.

I'm heading south for February next year for a trip. I'll look out for you. Can't be too many red yachts. Mine is green ketch.
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Old 18-07-2014, 16:59   #67
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Re: Solar and AGM'S

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Originally Posted by Maine Sail View Post
Odyssey Battery:
"When using a charger with the IUU profile, we suggest the following ratings for your ODYSSEY battery. Note the charger current in the bulk charge mode must be 0.4C 10 or more."
0.4C on a typical 600-700Ahr bank is 240-280A. Few have that capacity. If this is truly necessary, then buying these AGM batteries is a fool's game.

I suspect that they make this distinction because high C rates come closer to guarantying a full recharge than low C rates due to time and nothing else.

The AGM industry recognizes they have an Achilles heel with respect to deep discharge and not fully recharging - which is typical life on a boat.

Besides, you and others have actual data supporting that these high C currents can only be supported for a short time before absorption voltage is reached and they taper quickly after that.

So what is the point of high C currents besides shortening recharge time?

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Old 18-07-2014, 17:29   #68
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Re: Solar and AGM'S

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Originally Posted by Maine Sail View Post
As I stated earlier the Sterling can not to a proper float voltage IF your factory regulator is set higher than you need to do a proper float. There are diodes in the output path that drop it about .3V - .4V but if your factory alt is set at 14.6V or 14.4V or even 14.2V then you will not get the 13.4V - 13.6V one may desire.. They really do not do the same thing IF you actually need a float voltage, and most sail boats won't need float for an alternator.....
Thanks MS.

I should have elaborated that part but this gets way confusing for the average road warrior, very quickly.

My opinion is the Sterling can dramatically shorten the bulk phase (which is what most folks want)

For those with solar I always presume the "end of charging" whether it goes to float phase or not is handled by the solar. So let's get as many amps in from teh engine as we can in the minimum time.

The rest of this is not aimed at you but my observation on this thread.

I think the real question most people want to ask, or should be asking is - I have setup XYZ. How do I minimize running the diesel engine and still take reasonably good care of my battery bank.

For many it's cut back consumption, some it's more solar, for others it could be this Sterling. For some it could be a whole new alternator/regulator combo.

A ground up system can go "gold" plated. For most it's not necessary.

I am amazed how everyone throws out their solution and never ask, "How are you using the boat?"

TedSherrin (OP) in this thread is a weekend warrior. Why have $5000 worth of generating gear sitting unused 300 days a year?

Ted's original request could be summarized as, "How do I keep the beer cold for the weekend or a week on the hook."

I charter boats a fair bit (at least once a year) - I seem to have a great time and these boats don't have 1,000 a/h and 800 watts of solar.

Yup - I run the engine a lot...

We all need to be e bit more open minded and solve the OPs question, not just thrust our paradigms on them...

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Old 18-07-2014, 17:59   #69
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Re: Solar and AGM'S

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Originally Posted by Maine Sail View Post
As I stated earlier the Sterling can not to a proper float voltage IF your factory regulator is set higher than you need to do a proper float. There are diodes in the output path that drop it about .3V - .4V but if your factory alt is set at 14.6V or 14.4V or even 14.2V then you will not get the 13.4V - 13.6V one may desire.. They really do not do the same thing IF you actually need a float voltage, and most sail boats won't need float for an alternator.....
Thinking about this a bit because we just had to motor for 24hrs and used the engine with the internally regulated OEM alternator on it and not the engine with the externally regulated Balmar.

We have flooded batteries.

We started the trip at about 60% SOC and the batteries reached full charge after a while. Then for the rest of the trip, with the AP, running lights, instruments, etc, the batteries sat at 13.8V with the residual current (that remaining after running the above) at less than one amp.

The battery temperature during this was 90F (which was the air temp of the battery compartment itself), and the batteries were not gassing. As far as I could tell, these batteries were quite happy being kept at 13.8V with <1A current, and we could keep motoring for days/weeks like this with no ill effect.

So I am having trouble seeing why a "proper float" is a necessary thing for an alternator. Automobiles certainly do not have it, and most recreational boats that spend a lot of time motoring on full batteries do not have it.

Cruising boats, like you mention, will rarely see float unless they have to motor for many, many hours, or start out motoring with full batteries. Once they do reach float, it doesn't seem like splitting hairs over the difference between 13.4V and 13.8V makes much of a practical difference unless one planned to motor for many weeks straight.

Something like the Sterling device would never be used to keep a battery in float mode over longer periods of time (like a shore charger), and when it does reach "float", it is no different (actually a little better) than the internally regulated alternator you have anyway.

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Old 18-07-2014, 18:04   #70
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Re: Solar and AGM'S

what the OP should do is dump the AGMs, thee batteries have no useful place on a typical boat. You cannot use the advantages and the disadvantages are all present

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Old 18-07-2014, 18:11   #71
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Re: Solar and AGM'S

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Originally Posted by Ex-Calif View Post
Thanks MS.

TedSherrin (OP) in this thread is a weekend warrior. Why have $5000 worth of generating gear sitting unused 300 days a year?

Ted's original request could be summarized as, "How do I keep the beer cold for the weekend or a week on the hook."

I charter boats a fair bit (at least once a year) - I seem to have a great time and these boats don't have 1,000 a/h and 800 watts of solar.

Yup - I run the engine a lot...

We all need to be e bit more open minded and solve the OPs question, not just thrust our paradigms on them...

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Thanks Ex Cal, that pretty well sums me up, yes. Once a year I'm planning on up to a month long off sure trip (which I have done three times so far). Other than that weekends, three days at the most. I'm preparing my boat firstly for long service leave in four years when I'll leave for 3-4 months and do an East Australian coaster or NewZealand. And I'm so looking forward to retirement (but that's about 15 years away).

But you have hit the nail on the head. I'm a weekender who wants to have the luxary's of life (cold beer and sci fi movie on the tv) and do the occasional longer trip. I don't mind an initial spend up on quality items like spending $1300 on new AGM, and new solars. My concern around the AG m is simply to make sure I don't damage them. Basically everything I'm doing is intended for long term. But I don't want to spend $6-800 on an items I will get little use for until I retire.
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Old 18-07-2014, 18:18   #72
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Re: Solar and AGM'S

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what the OP should do is dump the AGMs, thee batteries have no useful place on a typical boat. You cannot use the advantages and the disadvantages are all present

Dave
Dave - Always respect your opinions and posts.

But this one is a "once size fits all" answer.

There are millions(?) of AGMs installed in boats.

It's a reasonable choice for a lot of folks.
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Old 18-07-2014, 18:38   #73
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Re: Solar and AGM'S

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Originally Posted by tedsherrin View Post
My concern around the AG m is simply to make sure I don't damage them.
If you want to ensure as much as possible you won't damage your battery bank, then get flooded batteries. These take almost anything you can do wrong and still love you for it. Even if you are in some way so evil you boil them dry and completely short them, they are relatively inexpensive to replace.

Kind of like a cross between a labrador and a cat.

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Old 18-07-2014, 18:54   #74
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Re: Solar and AGM'S

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Originally Posted by Ex-Calif View Post
Dave - Always respect your opinions and posts.

But this one is a "once size fits all" answer.

There are millions(?) of AGMs installed in boats.

It's a reasonable choice for a lot of folks.
Of course , the industry has promoted AGMs as a kind of "super" LA

AGM Positive
Low self discharge, rarely useful on a boat with shore power these days
High C charging, few have the equipment to to just that
Sealed - well if you boat is upside down , a little acid spillage may not be your first concern
Charge efficiency , in reality with the difficulty of returning to 100% this is not attainable

AGM Negatives
Charging Profile - more sensitive to having a particular charging profile
100% recharge - often requiring a return to 100% which is difficult
Sealed - as per all sealed batteries

The fact is the benefits can rarely be accessed and the negatives are typically always present.

I cannot see any reason to buy them , but please put forward one.

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Old 18-07-2014, 20:31   #75
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Re: Solar and AGM'S

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Originally Posted by goboatingnow View Post
Of course , the industry has promoted AGMs as a kind of "super" LA

AGM Positive
Low self discharge, rarely useful on a boat with shore power these days
High C charging, few have the equipment to to just that
Sealed - well if you boat is upside down , a little acid spillage may not be your first concern
Charge efficiency , in reality with the difficulty of returning to 100% this is not attainable

AGM Negatives
Charging Profile - more sensitive to having a particular charging profile
100% recharge - often requiring a return to 100% which is difficult
Sealed - as per all sealed batteries

The fact is the benefits can rarely be accessed and the negatives are typically always present.

I cannot see any reason to buy them , but please put forward one.

dave
Dave, I think you have forgotten another positive of AGM, and that is they are maintenance free. A fairly key aspect I'd think. It's certainly my main reason for looking to them at all. And apparently a 120 ah AGM battery is the equivalent of a 130ah wet cell. That's what I've been repeatedly told by people quoting me on AGM's this week.

Cost? I keep hearing on CF that there much more expensive than wet cell. Well, I'm not convinced that's true. Compared to a car battery, well yes AGM are dearer. But comparing AGM to 'Marine' wet cell, deep cycle batteries there relatively the same price unless going to the upper high industrial AGM's. I'm looking at 120ah AGM's. Because I'm buying four of them, I can get them for $330 each. Wet cell Marine wet cell battery prices for 130ah $280 to $340 for an optima. So for the sake of going maintenance free it would seem the AGM are ahead.

Now, because I want 'maintenance free' and leak and gas proof, AGM seem to be the way to go. But I'm also aware that I can get 'maintenance free', wet cells. But, when I've asked about them, for the purpose of a boat, the shop attendants have suggested not a good idea for a sail boat and their longevity is no where near as good as an AGM.

So, this has led me back to AGM's again. I'm not really picking up 'any' real practical reasons not to have them but I see lots of positives. You have suggested two 'negatives', one being charging profile to which they are sensitive to. Ok, but from what I'm picking up as long as I have a big enough bank for my use, the upgrade in solar and my 90amp alternator will suffice. I think that's what I'm picking up. Your second negative is that they require 100% recharge. Ok, so for a 480ah bank (4x 120), I'm still picking up that my two 120watt solar panels and 90amp regulator (obviously for boosting) would bring them up to 100%?

And my vessel lives on a mooring so I don't have the luxury of shore charging. Though my boats set up for 240v with a marine shore charger. The mooring makes this not possible.
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