When Towing The TM Which Regulator Controls Battery Charging?

[Philip]

Originally Posted by ZekenSpider

Phil;

I am attaching two .pdf files about the WFCO converter that came with my 3326. I think the three modes of operation are discussed in detail, but I suspect they are not adjustable without some sophisticated, board level knowledge.

Perhaps WFCO can supply that detail.

Regards,

Jerry

Hello Jerry,

Thank you for the great information. Just what I need.

The spec sheet is for my exact model series and shows the voltage points for Bulk, Absorption and Float. The The bulk and float look good for AGM batteries but the Absorption voltage is low(13.6) as opposed to the 14.27 that Lifeline wants. If it is going to be off I would rather have it low. I assume it will just take longer to charge. Over voltage I know will reduce battery life.

I would agree with you that there is no way to change the voltage set points.

Maybe an AGM could live with this charger fairly well.

I am going to check the voltage output of my TV regulator as soon as I get a chance to see what it is. The results of this will determine if I spend the extra money for an AGM battery. I will let you know the results of this but one can never be sure another auto regulator may be different so it would be best for you to check yours if you are considering an AGM battery.

Again thank you for all the help.

Take care,

Phil Friess

After reading Phils post I thought it would be interesting to see the response that Lifeline had to each of his points. And Phil please do not take the following the wrong way, it is just an attempt to ensure all of us can see both sides of the equation.

In response to the email you sent me regarding the blog post that you found. Most of this information contained in that blog post is incorrect. I am here to answer the concerns correctly and accurately based on actual real life testing, lab testing and published testing from us and other manufacturers. I am not sure what this gentleman does for a living but I know he does not manufacture batteries.

Let me start from the top. I will post his comments and then respond in red directly after each paragraph.

Blogger states “I have looked at the Lifeline website and read their comments comparing the AGM batteries with Gell batteries. I am quite sure this information is a lot of hype. Why - because while cruising on my boat for ten years, I ran into other cruisers who used AGM batteries and often got no more or less life out these batteries compared to Gell batteries. I got 12 years out of my three 8D gells and did absolutely no maintenance on them during that time. Live aboard cruising in remote areas where we cruised results in a huge demand on your batteries. Much, much more than RVing since you hardly ever plug in and your live aboard systems require many more amps than RVing.”

Lifeline Batteries information is not hype. We have a multi-million laboratory with high tech testing facilities. We produce many batteries for the military and commercial applications. We used to build Gel Cell batteries and they can be better, however they are not in any way a drop in replacement. You can get many years out of a Gel Battery if you have a proper charging system that could cost you thousands of dollars. What was happening in “real life scenarios” was customers were ultimately ruining batteries due to the lack of very sophisticated and controlled charging systems. Not to mention very different charging specs from any other battery. This is where AGM batteries come in. They are a very good sealed technology. They offer all the benefits of a sealed battery but you can upgrade from wet cell batteries in most cases without a charger upgrade. (details to follow later) Also being that this gentleman was a live aboard sailor brings a whole realm of new issues. First off, they do not charge back up to 100%. They usually claim they do not want to run their motors or generators that long. Reason being, is that the last 15% of battery charging takes the longest. This is not a good practice, however, I do understand why they do it. 60% of charge time is from 0 – 80% charged, and 40% of the charge time is from 80% to 100% charged. This is why they do not fully charge. The problem with this practice is they expect a battery to perform at 100% even though they are not recharging back to 100%. That’s like having a 100 gallon fuel tank, only putting 80 gallons in and expecting to get your full range out of it. What ends up happening is sulfation. Sulfation is a natural occurrence in all lead acid batteries. This includes WET CELL, GEL CELL, and AGM batteries. They all work the same. You have two plates. One is Lead and the other is Lead Dioxide. They all have an electrolyte. Ours is suspended in fiberglass matting. Gel batteries mix Acid with silica make a gelled electrolyte and the Wet Cell batteries are simply wet electrolyte that you replenish. Now when either of these batteries discharge lead combines with SO4 (sulfate) and create PbSO4 (lead sulfate), plus one electron. As the battery discharges, BOTH plates build up PbSO4 (lead sulfate) and water builds up in the acid. Being a lead acid battery ( and yes all Wet Cell, AGM and Gel’s are all considered lead acid batteries) they have a great feature. They can completely reverse PbSO4 by applying current to the battery. This removes the sulfation and returns the battery to a fully charged state. If any of the batteries sit discharged, the sulfation will harden and it requires equalizing (again explained below) to remove it. A controlled overcharge is the only way to rid of hardened sulfation. This is a great feature the AGM batteries and WET CELL batteries have but Gel batteries you cannot equalize. This means if the Gels are sulfated, that’s it. You have permanently lost capacity. Also remember that this is based on factual evidence. We used to build Gel Batteries so we could physically do a real side by side comparison. Now, he states he got 12 years out of his Gel cell batteries but what was the real life comparison. Did he do exactly the same thing for those 12 years that he did with every other set of batteries. Maybe he was plugged in a dock for 10 out of those 12 years. We get that a lot. Boat was in Seattle for 10 years and never left the dock for more than 2 weeks. Then they put our batteries in a sail to the south Pacific and expect another 10 years. That is just not a real life comparison.

Blogger states “1. How can an AGM Lifeline battery be a drop in replacement for a wet cell battery? Take a look at the Lifeline website and look at their Technical Manual for Lifeline Batteries on this website. Look at the charging requirements for these batteries starting on page 16. First they never tell you what the Voltage requirements are for the Bulk charging stage. Perhaps it is in a compatible range for a standard automobile regulator but who knows?? I believe most automobile regulators hold voltage at something like 14.7volts. Let's say the bulk charge from an auto regulator is ok. Look at the voltage requirements for the Absorption and Float phases of charging. I can tell you for sure that if you get to these stages while towing the auto regulator will be at too HIGH of a voltage for these phases which require 14.27 Volts(absorption at 80 deg.) and 13.25 Volts(float at 80 deg.). Lifeline is not telling you this but charging in this manner will surely reduce battery life.”

First of all just visit here and you can see Bulk Charging Voltages pretty clearly. http://www.lifelinebatteries.com/manual.pdf

In section 5.4 you will see battery charging. It states, right in the text not the chart, the Bulk stage will be constant current until the absorption set point is reached. Most people don’t know that this is how chargers work so I will explain this. All three stage chargers work the same. After a battery is discharged and you turn your charger on it will first go to Bulk Charge. This is the initial charge correctly called Constant Current. You will not see a high voltage right when it starts. The amperage will be really high and the voltage will be lower. Since the resistance is so low you do not need high voltage to push amps in. As it charges the voltage will slowly creep up to the absorption point. Once it hits the voltage set point on the charger, let’s say 14.4 volts, the charger will then switch to constant potential. In layman’s terms, constant potential locks the voltage at 14.4 and then the amperage will slowly creep down as the battery nears fully charged. Once the battery gets down to approximately 1 amp per every 100 amp hour of capacity the charger will then go into Float Mode. This mode will help maintain the batteries and help them achieve an actual 100% recharge. All the voltages at the certain temperatures that we list are ideal conditions but not necessary. These temperature figures are all based on optimum performance. If it’s 90 degrees out and you are charging at 14.5 volts you could shorten the life slightly. Not dramatically. If you are planning to go to extreme temperature conditions, then yes temperature compensation is recommended on our batteries, AS WELL AS WET CELL BATTERIES. I am sure you heard from someone that lives in Phoenix say that they have to water their batteries once a month. This is because his charge voltage is too high. Also, FYI almost ALL automotive regulators are 14.20 volts. All of the ones produced in the last 15 years have been this way.

Blogger states “Take a look at page 17 of the Lifeline technical manual. An AGM battery must me conditioned at times to maintain its capacity. A gell battery never has to be conditioned. The Gell manufacturers warn you against using a charger that does conditioning on a scheduled basis. They tell you that it will destroy a gell battery. Ok - so Lifeline tells you to condition their battery now and then. Read on in this section of the Lifeline Technical manual about conditioning. They go on on page 18 to warn you that conditioning must be done in a "well ventilated area" since hydrogen gases will be released during this procedure. Hydrogen comes from water being broken down with the charging voltages used during conditioning. How does the hydrogen get out of a sealed battery??? And how are you supposed to replace the lost water in a sealed battery??? The hydrogen must be forced under high pressure past the safety valve on the battery and you have no way of replacing the water. No matter what Lifeline says, this cannot be good for the life of a battery. Lifeline knows this and that is why they have all the qualifiers in the conditioning section of their manual. I think that this is a big part of why Gells tend to last longer with less maintenance than AGM's but alas Gells do require a much more precise charging regimen(tighter voltage control) than AGM's”

See next post for rest of response..

Here is the rest of the response from Lifeline:

Again bad information. It is a great thing that we can condition charge our batteries. Without this what if you accidentally left a light on and ran the batteries down and the sat for a month and they sulfate, as all batteries would, and you couldn’t recover them. Well that is the case with a Gel Cell. AGM and WET Cell batteries can both be recovered with equalizing. I am not sure why he states this is a big deal. This is a great tool to get more life out of your batteries. When he was cruising and only charging to 85% he should have been doing this once every 90 days to make up for the charging that he was not completing. A Gel Cell battery never has to be conditioned because it CAN’T. There is some gas that escapes from AGM batteries when equalizing. This is normal and yes as a safety measure the compartment should be ventilated. It is Hydrogen, so it is good practice to ventilate. Most likely very little will actually escape. We have 2 PSI safety relief valves in each cell that only vent if they have to as a safety feature. Very little water escapes during this process. Having a tiny little bit of hydrogen escape is far worth the capacity you would be normally losing due to sulfation. Although this could very slightly effect the life of the battery, it’s better to have to option to recover the battery back to 100% then to not have the option at all (Gel Cell Batteries). We have the qualifiers in our technical section simply to cover all basis so everyone that equalizes can do it safely by just reading our manual.

Blogger states “Another reason that AGM's may not be an effective drop in replacement for wet cells is that Lifeline also recomments that the regulation system also have temperature compensation(voltage adjusted as battery temperature changes. I believe I noticed this information in the Q&A section of the Lifeline website about charging. Gell manufacturers also recommend temperature compensation.”

Again, this is just a good measure to follow if you are going to be in extreme climates. Most all newer (last 10 years) charging systems have temperature compensation. We still get great life without it, but you can certainly extend the life with it. Most people do not realize that it is just a harmful to undercharge than it is to constantly overcharge, if not worse. You can find this information on everyone’s website. Undercharging is just as bad. Even some of the wet cell manufacturers are recommending, and again it’s a recommendation, to use temperature compensation to achieve maximum life. In close, this was very inaccurate information regarding Lifeline Batteries, as I cannot speak for all AGM batteries. Most of the Chinese equivilents are very poorly made and I will not recommend anything for those batteries. Discover and Full River are very poorly made Chinese knock offs. East Penn Deka is another American Made AGM. They also build a decent AGM battery but still recommend everything I have posted above. They also have a very detailed technical manual explaining everything I have explained here.

In close, AGM batteries might not be for everyone, but if you are going to upgrade to AGM batteries, it may be beneficial to upgrade the charger. Now a days, you can do it cost effectively. Xantrex makes two chargers, the Trucharge II and the XC Chargers. This will both give you temperature compensation and equalizing functions anywhere from $250.00 to $500.00.

Again this is not a necessity. Most battery chargers will work just fine with our batteries.

If anyone has any question or concerns, please feel free to contact Lifeline Batteries at 1-800-527-3224.

Nice post. I learned a lot.

it seems to me that the reason the post was so long was because a lot of documentation has been omitted by LifeLine. Or perhaps it is unclear.

The purpose of technical documentation is to eliminate questions from consumers.

In a perfect world, LifeLine, and perhaps other battery manufacturers, would see this post and update their documentation accordingly.

Unless there is an advantage for them to not do so.

Wayne,

Excellent point. It would make things much easier for people to make informed decisions if the documentation of a product would be all inclusive. Alas...that does not seem to be the way things are going. Trying to find out how things work is a never ending project. Witness the instruction manual for my Sony AVR. What is there, is the bare minimum. Thank goodness there are forums (like this one) where the more technical minded can help others.

Mike

Originally Posted by ragmopp

Wayne,

Excellent point. It would make things much easier for people to make informed decisions if the documentation of a product would be all inclusive. Alas...that does not seem to be the way things are going. Trying to find out how things work is a never ending project. Witness the instruction manual for my Sony AVR. What is there, is the bare minimum. Thank goodness there are forums (like this one) where the more technical minded can help others.

Mike

I get paid to write software for large mainframe systems. Every time a customer calls the service team there is a cost involved. Part of my job is to keep the call count as low as possible.

In my world customers do call. For consumer items, most customers will just never call, so hey get away with sloppy documentation.

[Philip]

Originally Posted by ragmopp

Here is the rest of the response from Lifeline:

Again bad information. It is a great thing that we can condition charge our batteries. Without this what if you accidentally left a light on and ran the batteries down and the sat for a month and they sulfate, as all batteries would, and you couldn’t recover them. Well that is the case with a Gel Cell. AGM and WET Cell batteries can both be recovered with equalizing. I am not sure why he states this is a big deal. This is a great tool to get more life out of your batteries. When he was cruising and only charging to 85% he should have been doing this once every 90 days to make up for the charging that he was not completing. A Gel Cell battery never has to be conditioned because it CAN’T. There is some gas that escapes from AGM batteries when equalizing. This is normal and yes as a safety measure the compartment should be ventilated. It is Hydrogen, so it is good practice to ventilate. Most likely very little will actually escape. We have 2 PSI safety relief valves in each cell that only vent if they have to as a safety feature. Very little water escapes during this process. Having a tiny little bit of hydrogen escape is far worth the capacity you would be normally losing due to sulfation. Although this could very slightly effect the life of the battery, it’s better to have to option to recover the battery back to 100% then to not have the option at all (Gel Cell Batteries). We have the qualifiers in our technical section simply to cover all basis so everyone that equalizes can do it safely by just reading our manual.

Blogger states “Another reason that AGM's may not be an effective drop in replacement for wet cells is that Lifeline also recomments that the regulation system also have temperature compensation(voltage adjusted as battery temperature changes. I believe I noticed this information in the Q&A section of the Lifeline website about charging. Gell manufacturers also recommend temperature compensation.”

Again, this is just a good measure to follow if you are going to be in extreme climates. Most all newer (last 10 years) charging systems have temperature compensation. We still get great life without it, but you can certainly extend the life with it. Most people do not realize that it is just a harmful to undercharge than it is to constantly overcharge, if not worse. You can find this information on everyone’s website. Undercharging is just as bad. Even some of the wet cell manufacturers are recommending, and again it’s a recommendation, to use temperature compensation to achieve maximum life. In close, this was very inaccurate information regarding Lifeline Batteries, as I cannot speak for all AGM batteries. Most of the Chinese equivilents are very poorly made and I will not recommend anything for those batteries. Discover and Full River are very poorly made Chinese knock offs. East Penn Deka is another American Made AGM. They also build a decent AGM battery but still recommend everything I have posted above. They also have a very detailed technical manual explaining everything I have explained here.

In close, AGM batteries might not be for everyone, but if you are going to upgrade to AGM batteries, it may be beneficial to upgrade the charger. Now a days, you can do it cost effectively. Xantrex makes two chargers, the Trucharge II and the XC Chargers. This will both give you temperature compensation and equalizing functions anywhere from $250.00 to $500.00.

Again this is not a necessity. Most battery chargers will work just fine with our batteries.

If anyone has any question or concerns, please feel free to contact Lifeline Batteries at 1-800-527-3224.

[Philip]

Originally Posted by ragmopp

Here is the rest of the response from Lifeline:

Again bad information. It is a great thing that we can condition charge our batteries. Without this what if you accidentally left a light on and ran the batteries down and the sat for a month and they sulfate, as all batteries would, and you couldn’t recover them. Well that is the case with a Gel Cell. AGM and WET Cell batteries can both be recovered with equalizing. I am not sure why he states this is a big deal. This is a great tool to get more life out of your batteries. When he was cruising and only charging to 85% he should have been doing this once every 90 days to make up for the charging that he was not completing. A Gel Cell battery never has to be conditioned because it CAN’T. There is some gas that escapes from AGM batteries when equalizing. This is normal and yes as a safety measure the compartment should be ventilated. It is Hydrogen, so it is good practice to ventilate. Most likely very little will actually escape. We have 2 PSI safety relief valves in each cell that only vent if they have to as a safety feature. Very little water escapes during this process. Having a tiny little bit of hydrogen escape is far worth the capacity you would be normally losing due to sulfation. Although this could very slightly effect the life of the battery, it’s better to have to option to recover the battery back to 100% then to not have the option at all (Gel Cell Batteries). We have the qualifiers in our technical section simply to cover all basis so everyone that equalizes can do it safely by just reading our manual.

Blogger states “Another reason that AGM's may not be an effective drop in replacement for wet cells is that Lifeline also recomments that the regulation system also have temperature compensation(voltage adjusted as battery temperature changes. I believe I noticed this information in the Q&A section of the Lifeline website about charging. Gell manufacturers also recommend temperature compensation.”

Again, this is just a good measure to follow if you are going to be in extreme climates. Most all newer (last 10 years) charging systems have temperature compensation. We still get great life without it, but you can certainly extend the life with it. Most people do not realize that it is just a harmful to undercharge than it is to constantly overcharge, if not worse. You can find this information on everyone’s website. Undercharging is just as bad. Even some of the wet cell manufacturers are recommending, and again it’s a recommendation, to use temperature compensation to achieve maximum life. In close, this was very inaccurate information regarding Lifeline Batteries, as I cannot speak for all AGM batteries. Most of the Chinese equivilents are very poorly made and I will not recommend anything for those batteries. Discover and Full River are very poorly made Chinese knock offs. East Penn Deka is another American Made AGM. They also build a decent AGM battery but still recommend everything I have posted above. They also have a very detailed technical manual explaining everything I have explained here.

In close, AGM batteries might not be for everyone, but if you are going to upgrade to AGM batteries, it may be beneficial to upgrade the charger. Now a days, you can do it cost effectively. Xantrex makes two chargers, the Trucharge II and the XC Chargers. This will both give you temperature compensation and equalizing functions anywhere from $250.00 to $500.00.

Again this is not a necessity. Most battery chargers will work just fine with our batteries.

If anyone has any question or concerns, please feel free to contact Lifeline Batteries at 1-800-527-3224.

Hello,

Not trying to get into an argument here but I do know that after 12 years of heavy duty cycles while cruising, the three 8D Gells I had onboard suffered very little loss in capacity without ever being equilized as Gell manufactuers recommend. I had a very accurate battery monitoring system to keep track of this. What is the purpose of a sealed battery if you need to vent each time you condition? Most all sailboats have their batteries stuffed in a tight enclosed space which is not conducive to conditioning!!

Oh - by the way, as I stated before, I was virtually never in a marina during these 12 years. Either sailing or at anchor!!!

Take care,

Phil Friess

[Bill]

Philip –

The discussion seems to have gotten off track here. My comments addressed solely the matter of AGM vs. flooded batteries. Now gel batteries are back in the mix.

Gels require a special charging regimen, as you noted in your original post. As you also noted, if you treat a gel cell properly, it is a very good battery. There is no argument here.

AGM batteries do not require a special charging regimen, which was your original question and the subject of my follow-up. I think you have agreed with this conclusion, though I’m not sure. Again, do you have information to the contrary?

As to whether or not AGMs are “worth it”, that is a separate question. And as to whether or not you can believe the manufacturers’ claims of extended life, that is also a separate question. You asked about charging regimens.

Like you, I tend to discount manufacturers’ claims for their own products. I try to find independent sources of info, from sources that are knowledgeable but don’t have a direct financial stake in selling you the product. On the question of batteries, there are many. I tend to like Northern Arizona Wind and Sun. They are a nationally-known company that deals with solar power systems, largely for homes, rather than RVs or boats. Their financial interest is in selling you a solar power system that you will like over the long haul. They don’t want to deal with unhappy customers, so they concentrate on good reliable equipment. They used to sell both AGM and gel batteries (as well as flooded). They dropped gel batteries, and they explain why in the tech library portion of their web site. They were just having too many calls from unhappy customers, because of the charging problems. If they sell you a gel cell and a special charger, all is well and they have a happy customer. But if they sell you a gel cell and you add your own charger, and the gel cell dies, guess who gets the nasty phone call? They got tired of that.

I included a link to Northern Arizona Wind and Sun in my post above. I think their explanation of the differences between the three types of batteries is comprehensive and quite understandable. They cover physical construction, charging requirments (and why gels are different), recombination of hydrogen and oxygen, lifetime, cost, and other interesting topics. You might read it.

So again, on the question of whether AGMs require a special charging regimen, the answer is “No”. Are they worth the extra cost? That is a separate question and different people will have different answers.

Bill

[Philip]

Originally Posted by Bill

Philip –

The discussion seems to have gotten off track here. My comments addressed solely the matter of AGM vs. flooded batteries. Now gel batteries are back in the mix.

Gels require a special charging regimen, as you noted in your original post. As you also noted, if you treat a gel cell properly, it is a very good battery. There is no argument here.

AGM batteries do not require a special charging regimen, which was your original question and the subject of my follow-up. I think you have agreed with this conclusion, though I’m not sure. Again, do you have information to the contrary?

As to whether or not AGMs are “worth it”, that is a separate question. And as to whether or not you can believe the manufacturers’ claims of extended life, that is also a separate question. You asked about charging regimens.

Like you, I tend to discount manufacturers’ claims for their own products. I try to find independent sources of info, from sources that are knowledgeable but don’t have a direct financial stake in selling you the product. On the question of batteries, there are many. I tend to like Northern Arizona Wind and Sun. They are a nationally-known company that deals with solar power systems, largely for homes, rather than RVs or boats. Their financial interest is in selling you a solar power system that you will like over the long haul. They don’t want to deal with unhappy customers, so they concentrate on good reliable equipment. They used to sell both AGM and gel batteries (as well as flooded). They dropped gel batteries, and they explain why in the tech library portion of their web site. They were just having too many calls from unhappy customers, because of the charging problems. If they sell you a gel cell and a special charger, all is well and they have a happy customer. But if they sell you a gel cell and you add your own charger, and the gel cell dies, guess who gets the nasty phone call? They got tired of that.

I included a link to Northern Arizona Wind and Sun in my post above. I think their explanation of the differences between the three types of batteries is comprehensive and quite understandable. They cover physical construction, charging requirments (and why gels are different), recombination of hydrogen and oxygen, lifetime, cost, and other interesting topics. You might read it.

So again, on the question of whether AGMs require a special charging regimen, the answer is “No”. Are they worth the extra cost? That is a separate question and different people will have different answers.

Bill

Hello Bill,

Yes you are correct - we have perhaps gotten off track here!

I always said AGM batteries were a vast improvement over wet cell batteries and explained why.

I knew from the beginning that I was not going to upgrade the TM with the sophisticated charging system that a Gell requires so my concern was always whether AGM battery life would be reduced significantly with the existing charging system in the TM AND the TV. I felt, and still do, that the only way to answer that question is to look at the charge points the AGM manufacturer recommends(for three stage charging) and see how much my charging system deviates from his recommendations. No matter what the AGM representative says in his previous post, the life of the battery will be decreased as you deviate from the optimal charging recommendations(if you read the AGM reps post closely he even states this in a backhanded way when he says it is better to have temperature regulation to further refine charging voltages).

So - where am I now in my evaluation.

Thanks to another poster, Jerry, I now have the voltage set points for my TM three stage regulator. Comparing them to the recommended voltages in the Lifeline online specification I come up with: Bulk; 14.4V for TM & 14.4V for AGM: Absorption; 13.6V for TM & 14.27(at 80 deg.) for AGM: Float; 13.2V for TM & 13.25(at 80 deg.) for AGM. The Bulk and float look fine but the Absorption is quite a bit low which I would have to assume will extend the time required to get a full charge or prevent getting a full charge period. This is not good for my use or good for battery life(as even the AGM rep. admits).

As far as charging the AGM with the TV, using the figure of 14.2V output stated by the AGM rep.(I will check this when I have the chance), It is appears acceptable for Bulk and Absorption. Unless it automatically cuts down(which I doubt it does[will check this also] to a lower voltage for float it is way to high for the AGM float voltage(13.25V). If you drive a long time with the battery fully charged, I fail to understand how it could not reduce battery life. Perhaps it might be best to not charge the AGM up full by plugging in before going on a many day towing trip.

For me the bottom line is that what I have now is NOT an optimal charging system for an AGM and will shorten battery life. How much will it be shortened I guess that even the AGM rep. could not tell me. I will probably have to experiment with an AGM battery to find out. Yes it is an expensive experiment but as I said before, I continue to believe that an AGM is a vast improvement over a wet cell as far as maintenance and durability. Even with this less than optimal charging system I hope to get much more life out of the AGM(with less maintenance) than a wet cell. Time will tell.

I will let this site know if I only get what I would consider to be wet cell life out of the AGM. I will also let this site know if I get good life out of the AGM(although this, I hope, will be longer than I may own the TM).

One more comment on your post. In the last paragraph you state "So again, on the question of whether AGMs require a special charging regimen, the answer is “No”. Are they worth the extra cost? That is a separate question and different people will have different answers." I still cannot agree with this statement. All batteries require a specific charging regimen for optimal life. Why do AGM and all other battery types have recommendations for charging points? Why does the AGM spec. sheet on their website go into specifics on a charging regimen? Even the AGM rep. stated that these are the best charging points for best battery life. So, the answer in reality is that correct charging regimen effects battery life. Yes, different battery designs are more tolerant of incorrect charging regimens but bad charging regimens will effect any batteries life.

Take care and thanks to all(even the AGM rep. - LOL!!) on this site for all the help,

Phil Friess