Batteries - conventional ver. AGM

[zero]

I just got in an argument with someone bragging up AGMs and how great they are, as compared to conventional batteries.  Note - I just bought a new battery bank and did some comparisons.  I picked the 6 volt golf-cart type of deep-cycle battery but these sort of results repeat themselves with most versions of the batteries (if not all).

I just bought new batteries for the battery bank in my cabin.  Conventional flooded-lead-acid batteries were a far better choice then AGMs.  There is a lot of hype about AGMs and much is BS.  For example, here are two Trojan deep-cycle batteries compared. Conventional FLA and AGM. Both T-105 batteries.

Note - the standard NON AGM version is lighter, cheaper, lasts longer, and stores more power.  Why on earth would someone want to pay more for a shorter-lived AGM unless you have a space ship and fly upside-down a lot?

Also, besides price - a few advantages with the cheaper conventional battery.  A 12 volt battery can be charged at 16 volts to "equalize" and the AGM can NOT.  AGM has a max charge voltage of 14.7 volts. And discharge?  The conventional battery can be discharged many times (750) to a full 100% discharge.  The AGM can not and is only allowed a discharge to 80% before it is ruined.

Life? (note - AGM does not allow 100% discharge, FLA does)
AGM - 20% discharge will last 2800 cycles,  80% - 500 cycles
FLA - 20 % discharge will last 4000 cycles, 80% - 1000 cycles

Price
AGM Trojan Reliant T-105 AGM   $245
FLA Trojan Plus T-105  $145

Weight
AGM Trojan Reliant T-105 - 68 lbs.
FLA Trojan Plus T-105  - 62 lbs.

Cold weather performance
AGM Trojan Reliant T-105 - 20 below zero F - 30% charge
FLA Trojan Plus T-105 - 20 below zero F - 30% charge

Amp-hours
AGM Trojan Reliant T-105 - 217 AH @ 20 hour rate
FLA Trojan Plus T-105 - 225 AH @ 20 hour rate

AGM Trojan Reliant T-105 charge rate - 7.35 volts MAX for a 6 volt battery
FLA Trojan Plus T-105 - up to 8.1 volts for a 6 volt battery

Ventilation?  Both versions require ventilation although an AGM puts out less gas

 

[bufbooth]

Most of my experience on AGM batteries is with my enduro motorcycles and my Mazda Miata.

On my motorcycles I have noticed about twice the battery life (in years) over past lead acid ones, so I like them for my motorcycles.

On my Miata, AGM was a requirement due to the battery being in the trunk, AGM has less vapors, and better handle being crashed into.

Dennis...

 

[payaso del mar]

5 hours ago, jdemaris said:

unless you have a space ship and fly upside-down a lot?

technology that isn't perfect and has some downsides?  say it isn't so!  my perpetual motion machine has none.....

i'd be the first to agree that, like silicone brake fluid and braided Spectra line, the considerable benefits have been grossly overhyped and the downsides minimized by some proponents.  HOWEVER, for some of us, the nonspillable aspect and vastly reduced (to almost nil) hydrogen output are worth the extra $ and limitations for a mobile vehicle.  even if I try to avoid flying, there;s this concept called crashworthiness in the event i get hit by someone else.  or if  i'm in the UP (or New Mexico mountains) and unexpectedly run into some black ice....     different balance of considerations than your (presumably-immobile) cabin. 

Even in my spaceship, I find the AGM works better in the zero-grav conditions.....with the FLAs, blobs of sulfuric acid electrolyte kept getting loose and floating around the cabin every time I checked the level.....nasty stuff to get in your eyes. 

our Subaru is being slowly and inexorably eaten by an acid leak from a long-since-replaced FLA (Bosch, defective case was cracked from factory, Pep Boys replaced), despite an orgy of repeated rounds of baking soda slurry and pressure washing to try to remove and/or neutralize it.............my wife now understands why I like AGMs. 

honestly, i'm surprised the price point on those Trojans was that close...I usually expect to pay 2X for AGMs

[payaso del mar]

Dennis raises another good point:  for offroad use, AGMs (at least, Optimas) tend to stand up to vibration better than FLAs......

[RVdaytrader]

Lifeline AGMs .......

LIFELINE RV BATTERY BENEFITS

Superior Construction-
Aircraft class cell construction; lowest internal resistance that provides high repeated cranking current.

Unmatched Life-Cycles-
When discharged to the BCI recommended 50%, Lifeline batteries provide nearly 1000 life cycles, which is significantly more than other technologies. Other flooded and gelled batteries fall between 300 to 450 life cycles at 50% discharges.

Rapid Recharge-
Lifeline Batteries facilitate a significant increase in recharge rate, with amazingly high current limitations when you properly regulate the charging voltage. Customers charge 100ah batteries with 500amp chargers routinely. 

The batteries can be charged with  a 500 amp charger!....not that anyone has one!!

[payaso del mar]

great specs, but those Lifelines are even more expensive than most AGMs:  http://search.defender.com/?expression=lifeline+AGM&x=0&y=0

[zero]

2 hours ago, RVdaytrader said:

Lifeline AGMs .......

Unmatched Life-Cycles-
When discharged to the BCI recommended 50%, Lifeline batteries provide nearly 1000 life cycles, which is significantly more than other technologies. Other flooded and gelled batteries fall between 300 to 450 life cycles at 50% discharges.

Rapid Recharge-

That claim is obviously not true and easily disproven.  Many FLA batteries with same size and AH rated as their AGM counterparts can be cycled twice what the AGMs can.

[zero]

4 hours ago, bufbooth said:

Most of my experience on AGM batteries is with my enduro motorcycles and my Mazda Miata.

On my motorcycles I have noticed about twice the battery life (in years) over past lead acid ones, so I like them for my motorcycles.

On my Miata, AGM was a requirement due to the battery being in the trunk, AGM has less vapors, and better handle being crashed into.

Dennis...

 

I've had exactly the opposite experience with batteries in my ATVs (4 wheelers).  The standard batteries have often lasted me 8 years.  Now - at least locally for the battery sizes I need - only AGMs are available and they have been horrible.  In fact, with one - we had three go bad in two years.  I am sure that is not the case with all AGMs but certainly is with the ones I got (made in China).  The flooded lead acid battery in my Honda CL175 came from Walmart and it 10 years old. Sat stored in a barn for 10 years and was stone dead when I pulled it out.  To my amazment, it had never frozen or cracked, and took a charge and is working.  One of those Yuasa made in Japan batteries.

[zero]

2 hours ago, RVdaytrader said:

Lifeline AGMs .......

LIFELINE RV BATTERY BENEFITS

Unmatched Life-Cycles-
When discharged to the BCI recommended 50%, Lifeline batteries provide nearly 1000 life cycles, which is significantly more than other technologies. Other flooded and gelled batteries fall between 300 to 450 life cycles at 50% discharges.

Rapid Recharge-
Lifeline Batteries facilitate a significant increase in recharge rate, with amazingly high current limitations when you properly regulate the charging voltage. Customers charge 100ah batteries with 500amp chargers routinely. 

The batteries can be charged with  a 500 amp charger!....not that anyone has one!!

What BS !

Trojan T-105 flooded lead acid life cycles: 100% discharge - 750 cycles, 50% discharge - 1600 cycles
Lifeline AGM :  100% discharge - 375 cycles, 50% discharge - 1000 cycles

And charging a 100 AH battery at 500 amps?  Cute trick when the battery temp on a Lifeline is not allowed to exceed 130 degrees F . Also Lifeline says charge rate on any of their AGMs should be 5% of the 20 hour rated capacity which is not very much.

[payaso del mar]

57 minutes ago, jdemaris said:

I've had exactly the opposite experience with batteries in my ATVs (4 wheelers).  The standard batteries have often lasted me 8 years.  Now - at least locally for the battery sizes I need - only AGMs are available and they have been horrible.  In fact, with one - we had three go bad in two years.  I am sure that is not the case with all AGMs but certainly is with the ones I got (made in China).  The flooded lead acid battery in my Honda CL175 came from Walmart and it 10 years old. Sat stored in a barn for 10 years and was stone dead when I pulled it out.  To my amazment, it had never frozen or cracked, and took a charge and is working.  One of those Yuasa made in Japan batteries.

Yuasa is the premier name in bike batteries, almost the only name aside from no-name.  Try Odysseys for bike AGMs, or better yet just get lithium.  probably not realistic to judge a technology based on how poorly the cheapest made-in-China knockoff of that technology works...............like saying Rolexes are junk cuz that Thai knockoff lost the krome and didn't work for long......

[zero]

As far as my bike goes, I'm comparing a FLA from Walmart as compared to an AGM from Walmart.  Same with my 4 wheelers.   I know AGMs, in general provide certain advantages that some people need and want to pay for. My point is - much of the advertising - especially over years from Concorde - have been hyped up.  Dollar for dollar, one buck buys more battery service with an FLA then an AGM.    FLAs on average, last longer then AGMs.   When you cut things down to verified facts - the advantages of an AGM for use in an RV are few.  One - they have a lower self-discharge rate which often means nothing to an RV owner.  Two - they are spill-proof that also likely means nothing to an RV owner.  Three, they off-gas less then an FLA which means nothing to me since my battery box is vented.  Four - they lose slightly less capacity at severe cold temps and again - in an RV that means nothing to me.    Disadvantages with an AGM?  One - shorter life when FLA "apples" are compared to AGM "apples."  Two - AGMs are often much more expensive.  Three - less tolerant to severe discharges then FLAs.  Four - less tolerant to high voltage charges e.g. "equalization." 

Also - Concorde, in their Lifeline manual  does not claim you can charge a 100 AH battery at 500 amps. It says it may be able to handle a "500 amp inrush."   I suppose that means momentary but it is not made clear.  Regardless - even if someone DID come up with a 100 AH battery that could handle, let's say a 500 amp charge -does anyone really care when it comes to an RV?  Personally, I don't want a "house" battery capable of nearly shorting out my alternator by offering nearly no rise in voltage and nearly unlimited charge rate. It would divert all alternator power to the "house" battery.  How is that an advantage in an RV?

[Gulfstream Greg]

I have had the same Lifeline AGM grp24 in service for almost 10 years now. Is it a 100% OK, probably not. But 10 years It has moved now through 3 RV's. I have another AGM (blue optima grp27) that I use for backup power for my ham radio station. AGM is perfect for my backup as it resides under my desk. It is constantly on an IOTA smart charger. I have an AGM for the starting battery for my backup generator. It is going on 15 years. It is constantly being chargerd by a wall wort charger that came with the generator. Personally I prefer AGM over FLA just because of the maintenance. Most everyone never checks the FLA batteries to see if they need water. Install and forget. Both technologies have their pluses. I have run down my lifeline agm to 6-11 volts on many occasions and left it that way for several weeks with out realizing it. It has always returned. On the other hand I have done the same with FLA batteries and it usually hurts them in the long run. 

[DanAatTheCape]

A few summers ago while wandering around Maine, happened to stay at nice CG and while using the laundry I saw a CD on deep cycle batteries.

 

they stated that  deep discharge of Lead Acid batteries will shorten the life.

eg  using a 75% discharge versus 50% will reduce the cycles a lot.

 

I do not recall the exact numbers but since then I have avoided running the house battery all the way down and I am still using that same battery/

In years long ago I had a deep cycle battery in a small fishing boat - ran it all the way down a few times and then it was basically worthless.

 

this is not the same video, but it is worth watching:  

 

 

 

Edited May 6, 2016 by DanAatTheCape

[DanAatTheCape]

and another article:   http://www.jamestowndistributors.com/userportal/document.do?docId=1019

[zero]

26 minutes ago, DanAatTheCape said:

 

 

26 minutes ago, DanAatTheCape said:

A few summers ago while wandering around Maine, happened to stay at nice CG and while using the laundry I saw a CD on deep cycle batteries.

 

they stated that  deep discharge of Lead Acid batteries will shorten the life.

eg  using a 75% discharge versus 50% will reduce the cycles a lot.

 

I do not recall the exact numbers but since then I have avoided running the house battery all the way down and I am still using that same battery/

In years long ago I had a deep cycle battery in a small fishing boat - ran it all the way down a few times and then it was basically worthless.

 

Some batteries are designed for deep discharges and some are not. It's not a matter of being lead acid, or not.   Trojan T105s are rated to survive being 100% discharged 750 times.  12 volt marine batteries at Walmart are rated to survive 250 discharges at 100%.  If you had a trolling battery that was ruined  by just a few 100% discharges, it was the wrong type battery for the job.

[payaso del mar]

also depends on how long it was left in a discharged state.

[Totem]

I hate AGM batteries; to me they are for weirdo environments where you want to fit one in sideways, or dont want to maintain them. they usually run great... for a year. they do take a physical beating and are the superior choice for enduro and jetski applications because of severe shocks encountered when jumping waves or dunes. Other than that, why bother. AGM - "always getting more" because they die every couple years.

In the I.T. world we use agm in arrays for UPS/APC to backup servers and computers as they can stay inside a disposable housing without needing to be touched; but even then they are off warranty in 3 years.

[Maineah]

I don't know but I can tell you from experience the AGM's last a long time. I have 35 amp take outs due to age not service life that are 15 years old from fire alarm systems still in use with my power supplies. Snow mobile batteries lead acid 1 year life span AGM's 5 years+ at $70 each for the flooded batteries or $100 for 4 more years I'll stick to the AGM's.

[Totem]

golf cart batteries (maintenance ones that have water add areas) I feel will run circles around wally world "marine starting batteries".

The new 4 battery golf cart bank i put in my cabin does simply amazing things and yet charges very well also off of solar.

I have two panel arrays with two separate controllers that dump into them, one is Poly and one set is Mono so that no matter what the sun conditions its getting something from at least one of the banks. Since doing this and dropping my old marine batteries I have noticed a SERIOUS performance gain in both charging and discharging.

[zero]

On average, AGMs don't last any longer then equivalent FLAs.  That is easy to verify.   Great to have in space ships and race-cars. No advantage for me other then a good way to make my wallet lighter.  They've been pushed and hyped for years - with one reason being they can be air-shipped and that makes getting them and selling them easier.   If you are a person that uses batteries forever, then you are paying X amount of dollars per month until you drop dead or wind up drooling in a  nursing home.   Conventional flooded-lead-acid batteries,on average, cost half what AGMs do.  That's all I need to know.  And yeah, there are many anecdotal stories of the "battery that lasted 15 years."  That goes for AGs and FLAs. Proves nothing.  I just replaced the battery in my 2002 Japanese-Ford tractor and it was still holding a charge.  Just a standard flooded-lead-acid  Yuasa battery.  So that's 15-16 years. It started going dead in a day or so if not left on a maintainer.  I'd be out of my mind to replace it with an AGM.   This spring - I checked the date-code on the two batteries in my Ford diesel truck and they were made in 2005.  Walmart-brand.  Still worked fine but I refuse to trust them when away from home and I just put two new ones in.  And yes, I've also had a few go bad in three years- especially if made by Exide.  Also note - I have three Duracell portable inverter/power-packs with 29 amp-hour AGM batteries.  They rarely get used and are always kept fully charged.  The batteries in all three went dead after exactly 5 years - like clockwork.  The first AGM replacement I bought was made in Viet Nam and it lasted 3 months.   The place that sells them said they've had lots of returns and sent me a Panasonic replacement that is now 3 years old and still fine. I cannot believe I'm buying products from 'Nam. Never thought it could happen in my lifetime - but that is a different issue.

My motorcycle batteries used to always be flooded lead-acid and usually lasted amazingly long (often over 10 years).  All my four-wheelers however have AGMs except one.  The one without the AGM has an 8 year old battery that is still fine.  I have had an awful time with the AGMs and two did not last 6 months.  That I am sure is a specific maker-problem and not just because they are AGMs.  I always got my FLA cycle and ATV  batteries at Walmart but now they are selling mostly AGMs and so far, complete crap.

The longest lived deep-cycle lead-acid batteries in the world are large, 2 volt, FLAs and they have projected lives of over 20 years.  

On the subject of batteries in battery banks?  E.g.Trojan versus Deka versus Walmart?   I've had banks with the 6 volt Trojan T-105s and the Deka GC-2s and also Rolls-Surette. All started to die from age after 8-9 years which is what they are expected to do. I do NOT expect a Walmart 12 volt  deep-cycle to last near as long.  If I get 5 years - I am fine with it. I like the convenience of the 12 volt batteries, like being available at any Walmart and also able to use in a farm tractor or boat when needed (cannot do that with a Trojan 6 volt). I also like less voltage loss or not needed extra big cables in my series connections in my 12 volt battery bank.  My 8 Walmart batteries cost me $656.  If I had gotten 8 Trojans it would of cost me $1160.  So yes, pay more and get more. Pay less and get less.  Also - I am aware of the Sams Club 6 volt GC2 Deka batteries sold for $83 each.  Looks like a good deal.  They are NOT the same quality or have the same life expectancy as Trojan T-105REs though.

[linda s]

I had to replace the starting battery in my Sunrader last year. Walmart battery. For some reason I thought I'd already replaced it once but I guess not. When I took it out I could see the date was 2004. My house batteries also from Walmart have always lasted at least 5 years. I'm very happy with their quality

Linda S

[payaso del mar]

ya know, I accept there is no comparison from a cost efficiency standpoint.  FLAs win, hands down.  I think I agreed with JD on that several pages back. 

 this isn't the total equation when installing lead-acid batteries in a movable vehicle, though....and not just "space ships and race cars".   most of those don't use lead-acid batteries of any kind anyway.....

some folks do think that nonspillability, no more acid vapor corrosion*, far less risk in an accident, ability to install most anywhere in any position, mostly zero maintenance for non-mechanical spouses to worry about, and reducing hydrogen outgassing to near zero is worth something, especially when considering batteries that will share the cabin of your RV with you.  it was many many years ago that the courts decided that being in a collision was a likely enough part of the expected service of a motor vehicle that the vehicle manufacturers had to consider safety in a reasonably expected crash in their engineering.  how would your house-battery box do in a rollover?

ultimately, I feel like we're beating two dead horses here, given that lead-acid tech is so archaic and will eventually be replaced by lithium or something else.  like I said, I want a Powerwall for my Bandit.  but I realize these two horses are the only affordable ones in town right now.........

* for this reason alone, many people go to AGMs, especially in higher end cars.  it kinda hurts to watch your 911R rust away in the area of the battery......  and battery tray corrosion is the single thing that killed more 914s than anything else.

[zero]

On 5/10/2016 at 5:56 PM, payaso del mar said:

 

some folks do think that nonspillability, no more acid vapor corrosion*, far less risk in an accident, ability to install most anywhere in any position, mostly zero maintenance for non-mechanical spouses to worry about, and reducing hydrogen outgassing to near zero is worth something, especially when considering batteries that will share the cabin of your RV with you.

* for this reason alone, many people go to AGMs, especially in higher end cars.  it kinda hurts to watch your 911R rust away in the area of the battery......  and battery tray corrosion is the single thing that killed more 914s than anything else.

I've got no argument with anyone who boasts the real virtues of AGM batteries and chooses to use them. My complaint is with the many that are evangelists for them, all over the Net, yet know little about them.   Like how they greatly outlast FLAs or are lighter, or have much more energy when cold, etc.  Most of that is pure nonsense.   Are they cleaner, yes.  .Do they off-gas less? Yes, even though they still require venting and if  your RV battery is in a vented box, what difference does it make? None to me.  I know of NO AGM sellers or makers that say no venting is required.  Being an all-position type of battery also is meaningless to me for use in my RV.  If I roll over, I assume I will have many problems.  AGMS do make sense when used in military air-craft. No argument there.  And they were indeed used in many race cars where it also makes sense (to me).

[DanAatTheCape]

On 5/6/2016 at 10:21 PM, jdemaris said:

 

Some batteries are designed for deep discharges and some are not. It's not a matter of being lead acid, or not.   Trojan T105s are rated to survive being 100% discharged 750 times.  12 volt marine batteries at Walmart are rated to survive 250 discharges at 100%.  If you had a trolling battery that was ruined  by just a few 100% discharges, it was the wrong type battery for the job.

Some batteries would be better then other brands.  My point is that a 75% discharge will cause a shorter life than a 50% discharge for all batteries.  And yes, leaving a battery less than fully charged will also shorten the life.

[zero]

Yes, but some batteries are ruined after 4-6 complete discharges, while other types are designed to sustain 1000 complete discharges. Not a matter of flooded-lead-acid versus AGM.  That is, except  the best flooded-lead-acid batteries are designed to sustain more 100% discharges then the equivalent AGMs.

[payaso del mar]

5 hours ago, jdemaris said:

evangelists for them, all over the Net, yet know little about them

true of a lot of products.  people don't usually want to bother learning more than the marketing buzzwords, and once they have dropped significant $ on something, they (at least subconsciously) want to believe that it's great (ie, they made a wise purchase).  the shrinks have a term for this but I forget it.  this is one reason many folks give things inordinately high ratings and why I always start by reading the worst reviews first.

[zero]

.On the subject of battery "BS" - I got into a slightly heated interchange last week with some people on the Chinook camper forum.   The big Chinook forum, not the one for little Toyotas.  A  "spokesman" there announced that Johnson Controls no longer makes any 12 volt batteries in the USA. He went further and claimed that no company makes a 12 volt battery in the USA anymore except for Deka.

I just bought 6 new Walmart  type # 27 deep-cycle batteries, made my Johnson Controls.   They also make Optima, Interstate, Sears Die Hard, Subaru, Honda, Duralast, and many many other brand names.  I contacted customer service with the code #s off of my new batteries.  ALL made in the USA two months ago.  The person at customer service told me that all their batteries are made in the USA unless marked with labels indicating otherwise.  I was also told that many batteries they sell in the Gulf Coast and California area do come from their plant in Mexico, simply due to it being closer.

[DanAatTheCape]

I had heard about the no lead batteries made in usa rumor.  I also read the explanation why that was BS. Not sure if I recall the details, but seems the gist of it was that ONE factory closed - one that made batteries out of 100% recycled lead.

 

Walmart uses Johnson Controls - they got away from them for a while but went back.  All in all, wallie's world has batteries that are a little cheaper & last a little longer.  Also since they are everywhere, easy to get warranty / replacement etc while wandering about.

[Totem]

On 5/13/2016 at 1:26 PM, payaso del mar said:

true of a lot of products.  people don't usually want to bother learning more than the marketing buzzwords, and once they have dropped significant $ on something, they (at least subconsciously) want to believe that it's great (ie, they made a wise purchase).  the shrinks have a term for this but I forget it.  this is one reason many folks give things inordinately high ratings and why I always start by reading the worst reviews first.

Agree, this will often leads to discussions of antimony content in plates, total weight and lead composition, battery size and height... etc.

To me it boils down to price, warranty and weight for example Interstate vs trojan golf cart batteries...one will cost $130 and one $80. But is the battery that's $130 REALLY $50 better than the other?