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Topic Review (Newest First)
09-19-2012 09:01 AM
Maine Sail
Re: Which AGM batteries are best

Here are some excellent links for some enlightening reading about a full time cruiser trying to use AGM batteries. I think John finally has it worked out but please DO read it all.. He eschews what I have been observing and trying to enlighten folks about for years. He does a GREAT job at nailing the "issues" and how to over come them.

These articles also display why I feel Lifeline battery is one of the best AGM makers out there. Justin has given John and Phyllis his full support and has NOT been bashful about having any of it posted on the internet so folks CAN get the best life out of Lifeline batteries..

AGM Batteries Test #1

AGM Batteries Test #2

Charging AGM's With An Alternator On A Cruising Boat

Problems With Using Battery Chargers To Charge AGM Batteries


18 Month Test Report

Equalizing Batteries On A Live-aboard Sailboat


Eleven Steps TO Better Battery Life

Direct Link To All John's AGM Articles
09-19-2012 08:21 AM
Maine Sail
Re: Which AGM batteries are best

Quote:
Originally Posted by SimonV View Post
From what I have read, one of the big positives for going from wet to AGM is you do not need to change your charging systems. When I bought my boat it came with Gels and I could not be happier, when i need to replace them it will be with the same.
You can often use flooded voltage settings but the acceptance rates of the batteries can tend to smoke small or factory alts not built to handle or disperse the heat. At a minimum I recommend an alternator temp sensor... I have two alternators on my bench right now both cooked by AGM banks.

With a single battery you can often do fine and some factory alts have built in temp compensation but you'll charge very sloooowly when they heat up. However when you get into bank of AGM this is where you really should complete the rest of the system.

These are expensive batteries that benefit from temp compensated charging and temp limited alternators will also benefit.

This is not just limited to AGM's and even a flooded bank that is much bigger than the alternator can suffer the same fate.
09-19-2012 07:54 AM
Maine Sail
Re: Which AGM batteries are best

Quote:
Originally Posted by chef2sail View Post
Fitting a larger alternator which I wanted to do with the serp belt was not an option to me due to the space my engine is in.

I guess I have wasted my money then as are many of us with AGM.
I guess the marine professional we deal with really isn't qualified in his recommendations
I guess the marine industry is duping many of us to buy the AGMs

One thing my marine professional has said to me is the same as you said. You can't beleive what you read on the Internet. Funny these comments are all on the Internet I am reading including the SailNet ones.

Luckily I have already gotten a few years on these Lifelines so I will be waiting for them to expire any day now. Or maybe they will actually last the 8 years I expected them to to beat all the negative expectations I keep reading about to make them financially worth while. I don't jut consider the initial cost of the batteries as the only cost. There is the other associated energy costs to keep them charged.

There is a space issue and access for maintainence which also lead to my decision. There was a safety one where I didn't want H2SO gasses on my boat and in the compartment where I live or spilling around if I had to ork on them around

One of the reasons I chose the electromax on your recommendation which was a good one was the % of charge at lower Rpm. I know that the bank should have a larger charger, but it simply won't fit.

I will show your post to my marine tech. Like both you and Bill it is what he does for a living and he is recognized by people in the Annapolis area as one of the if not the top company and person to use in this area. Maybe I as well have erred in using his advice and expertise. He is independent of brand use and presented me with 3 different scenarios for Haleakulas electrical system. This was the option he suggested. I tend to trust people I can look in the eye, but of course do research on line to try and back up my decision. What I read on the internet is all over the map. So who should I beleive? I choose the best I can from the informstion I get.

I will be interested in his reaction to you and Bills posts as he has a lot of real world experience and customers too.

Dave
Dave,

I don't think you've been "duped" as it sounds as if you made an "educated" decision. You may get your 8 years out of them for how you use them. As I recall you are on a dock. One of the big issues I face with cruisers and many of my customers is that they are not tied to a dock on a regular basis. AGM batteries like to get back to 100% and a dock sailed boat has this advantage over a cruiser or mooring sailed boat. I am still at a loss as to why a larger amperage Emaax would not fit? The 80A model and the 140A model share the same exact alternator case and have identical exterior dimensions.. Only the internals, stator & rotor, are different..

As I have said before AGM's can be the right choice, they have many benefits, space constraints are another good one, but I would be doing many of my customers a disservice by only recommending AGM because AGM's can be a poor choice in some applications for a number of reasons from financial to how the batteries will be charged.....

I install a lot of the 220Ah 6V 4CT batts because they are a standard height and will fit more Ah's than four group 24's will...
09-19-2012 06:34 AM
Minnewaska
Re: Which AGM batteries are best

Quote:
Originally Posted by SimonV View Post
From what I have read, one of the big positives for going from wet to AGM is you do not need to change your charging systems. When I bought my boat it came with Gels and I could not be happier, when i need to replace them it will be with the same.
I don't believe this is correct. An AGM will ruin your alternator or charger without proper voltage/temp regulation for the AGM style.
09-19-2012 01:47 AM
SimonV
Re: Which AGM batteries are best

From what I have read, one of the big positives for going from wet to AGM is you do not need to change your charging systems. When I bought my boat it came with Gels and I could not be happier, when i need to replace them it will be with the same.
09-19-2012 12:48 AM
chef2sail
Re: Which AGM batteries are best

Fitting a larger alternator which I wanted to do with the serp belt was not an option to me due to the space my engine is in.

I guess I have wasted my money then as are many of us with AGM.
I guess the marine professional we deal with really isn't qualified in his recommendations
I guess the marine industry is duping many of us to buy the AGMs

One thing my marine professional has said to me is the same as you said. You can't beleive what you read on the Internet. Funny these comments are all on the Internet I am reading including the SailNet ones.

Luckily I have already gotten a few years on these Lifelines so I will be waiting for them to expire any day now. Or maybe they will actually last the 8 years I expected them to to beat all the negative expectations I keep reading about to make them financially worth while. I don't jut consider the initial cost of the batteries as the only cost. There is the other associated energy costs to keep them charged.

There is a space issue and access for maintainence which also lead to my decision. There was a safety one where I didn't want H2SO gasses on my boat and in the compartment where I live or spilling around if I had to ork on them around

One of the reasons I chose the electromax on your recommendation which was a good one was the % of charge at lower Rpm. I know that the bank should have a larger charger, but it simply won't fit.

I will show your post to my marine tech. Like both you and Bill it is what he does for a living and he is recognized by people in the Annapolis area as one of the if not the top company and person to use in this area. Maybe I as well have erred in using his advice and expertise. He is independent of brand use and presented me with 3 different scenarios for Haleakulas electrical system. This was the option he suggested. I tend to trust people I can look in the eye, but of course do research on line to try and back up my decision. What I read on the internet is all over the map. So who should I beleive? I choose the best I can from the informstion I get.

I will be interested in his reaction to you and Bills posts as he has a lot of real world experience and customers too.

Dave
09-18-2012 10:00 PM
Maine Sail
Re: Which AGM batteries are best

Quote:
Originally Posted by chef2sail View Post
Our decision to use AGM was not an emotional one but suggested by the top marine professional in the Annapolis area who outfits many of the cruising boats in Annapolis area as well as teaching marine elctronics in seminars at many of the boat shows and for the Annapolis Seamaship school. There are many factors in to deciding to use them and they are not as said a panacea or answer for everyone. I beleive true marine elctronics professionals look at the whole situation, intended usage and make their decisions based on that.

One of the most widely used arguments against AGM/ Gell is that they are more expensive. But are they really? The initial cost of the AGM is not just the only factor here. The cost of charging them must also be brought into the equation. This includes the charger, the cost of the energy to run the charge ( be it engine or genset), also the rate of discharge. The following is qouted from an article:



Advancepowerproducts,com


Gell batteries from windsun.com - they create solar charging syetms



with the proper care this is not really true. Ask how many sailors actually equalize their lead acid batteries monthly properly


This is simply not the case. The technology of th AGM makes them much more resisitant to vibration. In addition with AGM you do not have ANY acid problem. With AGM you have No spilling acid on your clothes when filling them or testing them, No discoloration or repair in your battery comopartment as there is no gas or sulfuric acid mist emitted during charging like with wet cells. This gas smells like rotten eggs---ever wonder why and what it is ( it is sulfur)

I agree that AGM systems must be matched more carefully, however there is no limnited rate for charging as their is for wet cells


This has been discussed. Initially this is true, but when you add in the maintainence costs as well as the amount of the cost of energy ( wet cells take longer to charge to 100%, and must be charged at a higher point of discharge than AGM, and are less efficient in obtaining and making energy), ther longer the AGM lasts ( that is owners responsibility) the cost curve becomes a non issue. In other words a AGM which lasts 8 years will pay for the initial higher costs through the lower charging and energy efficiency costs. Plus NO Maintenence


Obvious turth as they have been around much longer. As time advances this will not remain the truth. If you are cruising to Vanatu or the Solomons Islands this may be an issue. If you are cruising on the Chessie, United States or Canada this is a non issue.

Lastly in this, I have on a number of times helped fellow sailors who have been involved in a knockdown or a rough passage to clean out their battery comparments where there was acid spill and incidents caused by the wet cells movement during the rough seas. For safety is is so very important to do a good job of tying down and isolating your batteries so they dont move. With AGM this is a non isuue

With all respect to Bill ( whose posts a have huge respect for and have followed his advice many times) I think the main point here is whether you want to have a maintainace free system. Yes it is more high tech, sort of. As Bill and Mainsail have pointed out AGM are not for everyone. The proponents of it however are not just highly energized users or purchasers of the batteries, but professional marine electronics technicians also. In some of the sailors on here it may be quite and advantage to utilize them, and in many not so much to justify the added expense. You will need to do the maintenance though.

Batteries purchase is right up their as a topic on here with correct anchor, sail material and firearms in its many dimensions and ability to energize ( I like this word as you see especially when discussing batteries) the posters on here. Is there an always right answer to this. NO I think not. It depends on you usage and abilities and dedication to electrical maintenance. To long distance cruisers who that's all they do is maintain their boats...no brainer. To the average weekend user, maybe a different story. All sides can find factoids to support their own conclusions, just as I have. My recommendations are to consult a local to you marine electronics professional to go over your specific usage and needs to help you make the most educated decision.

Dave
Dave,

You need to be careful with what you read on the internet. There are soooo many untruths and misrepresentations about AGM technology out there it can be simply laughable to those of us who work with deep cycle marine battery technology every day..

There are benefits to AGM batteries but much of what you read on the net about them is pure unadulterated BS...

In the real world of the marine environment GEL's typically last the longest, deep cycle wets not far behind and AGM, even if well cared for, come in behind both gel and wet. I would bet dollars to donuts that as a fellow marine electrical systems specialist Bill Trayfors sees the same as I do because I know we both on the same type of test equipment...

I base all my personal observations on battery life in the real world on actual measurements with industry standardized test equipment and the actual battery date codes. Most of the rubbish you read on-line about AGM's are white glove laboratory numbers not real world data like I see and deal with on a daily basis.

The sad reality is that perhaps 2-3% of the boats equipped with AGM technology actually take advantage of the acceptance rates and "faster charging" which IMHO is the real benefit to AGM's for "sailors" but there are other great benefits to AGM's...

IIRC your boat has an 80A Emaax alt and 660 Ah's of Lifeline AGM's. Even a 400Ah bank of wets would exceed the output of your alt in acceptance. Lifeline wants to see a MINIMUM of 0.2C or 20A per 100 Ah's of battery, for deep cycling applications. A MINIMUM of 20% of bank capacity.

If we figure your 80A alt can produce 70A when hot then you are at about 10.6% of capacity or roughly half of what Lifeline wants to see as a bare minimum. Wet cells will easily take 20-25%.. 25% of a 660 Ah wet cell bank would be an alt capable of 165A hot. That is more like a 180A "rated" alternator....

Lifeline actually warns that if the charging output is less than 20% of the banks capacity that cycle life can be "negatively affected". You can easily fit an Emaax 140 or 160 on that engine with a serp kit... I have done a number of 140A alts on 3 cyl Yanmar's..

Break in is also critical for all batteries and most yards, installers and boat owners are clueless about this. All batteries need to be cycled a few times and charged back to 100% capacity before the real capacity of the bank can be utilized.

When Bill talks about "abuse" I am fairly certain he means the "abuse" boaters put batteries through as in charging and discharging or lack there of, not vibration etc..

Still deep cycle wets and GEL's outlast AGM in my neck of the woods by a decent margin but about 85% of the boats I work on are mooring sailed and AGM's seem to dislike this more than flooded or gel banks (all based on real world, in the field, testing with industry standardized analyzers). I install a boat load of batteries, own the very expensive test equipment, install the charging systems and all I can say is AGM's CAN be the right choice but to do it right, which MOST don't do, can be a commitment and also costly.

As I said earlier AGM installations should be treated as a system and need to be treated as such. If they are properly installed they can come darn close to the life cycle expectancy of good deep cycle wets but I would not say I have ever seen them exceed wets in cycle life, even when properly installed.

I have the opposite problem on our boat. The alternator far exceeds our banks acceptance. I really could have an AGM bank, but I am waiting for my $210.00 bank of Wal*Mart wet cells, now nearing the end of their 6th season, to die. Can't seem to kill them though. BTW that same bank, if Lifeline, would have cost me $1170.00 at my cost.
09-18-2012 09:09 PM
chef2sail
Re: Which AGM batteries are best

chuckles.

Main may be right as Lifeline/ Odessey make all sorts of differeing footprints for the 6 volts other than the traditionl ones. We had that issue. I wound up making cardboard templates to make sure they fit before I purchased.

You access is great for maintainence

Dave
09-18-2012 08:56 PM
chef2sail
Re: Which AGM batteries are best

Quote:
I find the differing views on AGMs between typical users and marine professionals to be instructive.

AGM users either swear by them or swear at them. Often, though, they imbue AGMs with almost mystical properties which in the real world don't really exist. They also tend to dismiss older technologies, like flooded lead-acid batteries, and gelled lead-acid batteries as being "dangerous", "messy", or "easy to kill".btrayfors
Our decision to use AGM was not an emotional one but suggested by the top marine professional in the Annapolis area who outfits many of the cruising boats in Annapolis area as well as teaching marine elctronics in seminars at many of the boat shows and for the Annapolis Seamaship school. There are many factors in to deciding to use them and they are not as said a panacea or answer for everyone. I beleive true marine elctronics professionals look at the whole situation, intended usage and make their decisions based on that.

One of the most widely used arguments against AGM/ Gell is that they are more expensive. But are they really? The initial cost of the AGM is not just the only factor here. The cost of charging them must also be brought into the equation. This includes the charger, the cost of the energy to run the charge ( be it engine or genset), also the rate of discharge. The following is qouted from an article:

Quote:
AGM is more efficient.
Based on Peukert's equations, the German scientist who mathematically solved the battery discharge problem, each battery's efficiency can be computed. AGM batteries are generally far more efficient than are flooded lead acid batteries. This is important when determining the cost to charge and discharge the batteries. Generally an AGM battery will give you between 80-90% of the power pushed into the battery, back. On the other hand, flooded lead acid batteries typically have efficiencies in the 40-60% range. The bottom lines here are time and money. Basically you spend more to charge a flooded battery than you do an AGM. This translates to money as generators eat gas, alternators rob horsepower from the engine, and battery chargers eat kilowatts. The real tragedy is that you get less of that power back from the flooded battery than you do with an AGM battery.

AGM self discharge rates are 80% - 99% better.
Batteries, being a chemical equation in flux, are not perfectly stable. A battery will self discharge as it sits. AGM batteries are far more resilient than flooded batteries when it comes to self discharge. The typical AGM battery will discharge 1 to 3% per month, with this rate remaining stable over the life of the battery. Flooded battery models do not fare as well, losing 5-10% per month when new, and up to 20 or 40% per month as they age due to antimony contamination in the negative plates.
Advancepowerproducts,com
Quote:
Absorbed Glass Mat (AGM) batteries include lead plates packed between silica-glass mats, which hold electrolytes in suspension. They have no input current limitations allowing them to recharge more quickly than Flooded batteries, which typically accept about 35% of their ampere-hour rating, and Gelcells, that accept about 50%. At higher current loads AGMs also maintain usable system voltages for other high current, short duration loads as opposed to their counterparts, which become more inefficient during high current loads. AGMs also boast a longer lifespan than their counterparts, a deep-cycle flooded battery allows for 350 cycles at a 50 percent discharge level and Gelcells allow for 750 cycles whereas an AGM offers up to 1000 cycles at a 50 percent discharge level.
Gell batteries from windsun.com - they create solar charging syetms
Quote:
Gelled batteries, or "Gel Cells" contain acid that has been "gelled" by the addition of Silica Gel, turning the acid into a solid mass that looks like gooey Jell-O. The advantage of these batteries is that it is impossible to spill acid even if they are broken. However, there are several disadvantages. One is that they must be charged at a slower rate (C/20) to prevent excess gas from damaging the cells. They cannot be fast charged on a conventional automotive charger or they may be permanently damaged. This is not usually a problem with solar electric systems, but if an auxiliary generator or inverter bulk charger is used, current must be limited to the manufacturers specifications. Most better inverters commonly used in solar electric systems can be set to limit charging current to the batteries.

Some other disadvantages of gel cells is that they must be charged at a lower voltage (2/10th's less) than flooded or AGM batteries. If overcharged, voids can develop in the gel which will never heal, causing a loss in battery capacity. In hot climates, water loss can be enough over 2-4 years to cause premature battery death. It is for this and other reasons that we no longer sell any of the gelled cells except for replacement use. The newer AGM (absorbed glass mat) batteries have all the advantages (and then some) of gelled, with none of the disadvantages
Quote:
- flooded batteries will outlast AGMs every time in terms of charge-discharge cycles
with the proper care this is not really true. Ask how many sailors actually equalize their lead acid batteries monthly properly

Quote:
- flooded batteries will take a lot more abuse than AGMs
This is simply not the case. The technology of th AGM makes them much more resisitant to vibration. In addition with AGM you do not have ANY acid problem. With AGM you have No spilling acid on your clothes when filling them or testing them, No discoloration or repair in your battery comopartment as there is no gas or sulfuric acid mist emitted during charging like with wet cells. This gas smells like rotten eggs---ever wonder why and what it is ( it is sulfur)
Quote:
- flooded batteries do not require expensive upgrades of online charging capability
I agree that AGM systems must be matched more carefully, however there is no limnited rate for charging as their is for wet cells

Quote:
- flooded batteries are a lot cheaper than AGMs
This has been discussed. Initially this is true, but when you add in the maintainence costs as well as the amount of the cost of energy ( wet cells take longer to charge to 100%, and must be charged at a higher point of discharge than AGM, and are less efficient in obtaining and making energy), ther longer the AGM lasts ( that is owners responsibility) the cost curve becomes a non issue. In other words a AGM which lasts 8 years will pay for the initial higher costs through the lower charging and energy efficiency costs. Plus NO Maintenence

Quote:
- flooded batteries are available everywhere in the world
Obvious turth as they have been around much longer. As time advances this will not remain the truth. If you are cruising to Vanatu or the Solomons Islands this may be an issue. If you are cruising on the Chessie, United States or Canada this is a non issue.

Lastly in this, I have on a number of times helped fellow sailors who have been involved in a knockdown or a rough passage to clean out their battery comparments where there was acid spill and incidents caused by the wet cells movement during the rough seas. For safety is is so very important to do a good job of tying down and isolating your batteries so they dont move. With AGM this is a non isuue

With all respect to Bill ( whose posts a have huge respect for and have followed his advice many times) I think the main point here is whether you want to have a maintainace free system. Yes it is more high tech, sort of. As Bill and Mainsail have pointed out AGM are not for everyone. The proponents of it however are not just highly energized users or purchasers of the batteries, but professional marine electronics technitions also. In some of the sailors on here it may be quite and advantage to utilize them, and in many not so much to justify the added expense. You will need to do the maintainence though.

Batteries purchase is right up their as a topic on here with correct anchor, sail material and firearms in its many dimensions and ability to energize ( I like this word as you see especially when discussing batteries) the posters on here. Is there an always right answer to this. NO I think not. It depends on you usage and abilities and dedication to electrical maintainence. To long distance cruisers who thats all they do is maintain their boats...no brainer. To the average weekend user, maybe a different story. All sides can find factoids to support their own conclusions, just as I have. My recommendations are to consult a local to you marine electrontics professional to go over your specific usage and needs to help you make the most educated decision.

Dave
09-18-2012 08:31 PM
chucklesR
Re: Which AGM batteries are best

I'm hoping I can MS - but not optimistic. I can't measure the space right now for a variety of reasons. My impression when I inspected the boat is that basically the space was as you see it, not deep enough for 6v's or wide enough for 27's or 31's.
There's only about 2 inches of above the batteries clearance for those 24's.
You can use my size tens for reference.

I just stuffed a pair of 6v GC2's in my Gemini in June when my Optima's gave up the ghost (5 years of supposed good monitoring) - those 6v puppies are tall.
Saved 70 pounds and added 1/3 the AH though.
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