10 Facts About AGM Battery's

[saddlebum]

Found this on the web. Thought it might be of some interest.

10 Facts about AGM Batteries

1. AGM batteries were originally developed for the military and so are very robust and can take much more abuse than wet-cell or standard deep-cycle gel batteries. As the electrolyte is contained within the glass mats, there is nothing to leak or spill and they are relatively free from freezing damage.

2. As with other sealed batteries there is little to no maintenance with AGMs. Even more of an advantage is that most of them are 'recombinant'. What this means is that the oxygen and hydrogen combine inside the battery during charging cycles to form water - hence very little water loss and hydrogen emission. These batteries are therefore less hazardous than their counterparts.

3. AGM batteries can be stored in otherwise prohibited areas because of their advantages of no leakage and no fumes. Another advantage of this property is that they can be stored on end or on their sides if need be without damage.

4. The battery construction places the electrolyte in closer proximity to the active plate material. This enhances the efficiency of both discharge and charge cycles. Because of this, and because the internal resistance of the battery is very low they generally charge at a faster rate and to a higher capacity than non-AGM batteries. They can also take heavy discharge rates without damage and can take the occasional discharge below the recommended 50% of capacity rule.

5. AGMs have a very low discharge rate when stored for extended periods, and even if left to totally discharge in storage they can be quickly recharged back to over 95% of their capacity providing they have not been left too long in a discharged state. The advantage is, no flat battery after storing for extended periods (within reason of course).

6. Under normal operating conditions, a good service life of up to 5 years can be attained. With quality care and handling, managed discharge and charge even longer lifetimes are common. Some reports quote up to 10 years.

7. AGM batteries are quite a bit more expensive that conventional wet-cell and standard deep cycle. But if you measure this cost against their robustness, longer life expectancy and better performance, they still present as the best value for money over the longer term.

8. A 'normal' car alternator will only charge a wet-cell type battery to around 70-80% of its capacity. Because of its higher charging rates an AGM battery will just about fully charge and at a faster rate from the same type of alternator.

9. AGM batteries are capable of charging rates up to 75% of their rated ampere hour capacity. In some cases this can lead to damaged alternators or standard auto chargers that may be susceptible to the excessive heat generated when trying to deliver maximum amps. The good point though is that AGMs will charge at lesser rates and be quite happy doing that. But, if you are going to spend money on a quality battery then you should really be looking at buying a quality three-stage charger.

10. AGM batteries can handle a multitude of roles. They can be used as starting batteries, in deep cycle applications, or as standby batteries for critical powered systems. These reasons make them ideal for camping applications. They can also be connected in series or parallel banks providing for various terminal voltages and ampere capacities. Example: two AGMs can be wired in parallel in a pop-up camper. Charged via a three stage 'Smart' charger and never have an issue with them.

Edited March 11, 2012 by saddlebum

[Cougar]

Good Read, Thanks !

[Little Bob]

I am buying a Deka battery this week. I have a optmate 3 battery charger. Will that work on my new battery.

[warriorhoneybee]

wow,thanks for the info. so agm it is.

[Rocket]

I am buying a Deka battery this week. I have a optmate 3 battery charger. Will that work on my new battery.

 

That is what I use on mine.

[Bummer]

11. When an AGM battery starts to die it won't charge normally, leaving you looking for a jump at a restaurant in a small town in the middle of nowhere (or right next to it) in Montana.

12. You'll get the system tested at the Yamaha dealer fifty miles down the road and the battery will seem to work just fine.

13. You'll plan on getting a Buckeye stator until you try to start the bike in the spring after keeping it on a Battery Tender all winter, just to have the engine crank once then everything go black.

14. After checking all the fuses you'll go buy a Yuasa lead/acid battery for half the price of the AGM that lasted a year and a half.

15. You'll still consider buying a Buckeye stator since you just aren't sure what happened with that high-price AGM wonder battery.

 

Of course, it could just be me.

[gunboat]

been there, done that. hope to never have it happen again.

reguards

don c.

[Cdnlouie]

You know, I love the idea of an AGM too. Now, my first AGM was a Magna Charge off of ebay and it was sold as new but the manufacturer date was about 3 years old. It worked great for the first season, but then went dead over the winter while plugged into a battery maintainer (basic type). I boiled the heck out of it in the spring (nothing to lose) and got it working again for one more season (worked great as long as being used in the bike regularly). Did the same thing again the next winter so just decided to recycle it. Maybe I got a bad one here so I can't say that it it is the norm, but it is a bad experience so just tossing it into the ring. So far I prefer the lead acid with a good maintainer and I get lots of years out of them, at least five and usually more with basic Walmart specials.

[footsie]

I use the yuasa batteries, put one in and replace 5 or 6 years down the road

Have never had one go down in less than 5 years, had one last 7.

Have never had to do any maintenance on one.

They just last, so I don't look for anything different.

 

If ain't broke then don't try to fix it!

 

 

just my opinion

Gregg

[Snaggletooth]

I have to ask those that have had AGM batteries fail early in the game what brand they were?

 

With the kind of performance I've had with the DEKA line, four years now with no loss of power, I'm just curious.

 

Mike

[gibvel]

Had an Interstate crap out on me after 1 year.

 

So far so good with my Deka.

[Cougar]

have Odysseys (still good) and now a Deka. trying Deka this spring.

[Flyinfool]

First crack of an eyebrow was reading number 4

4. The battery construction places the electrolyte in closer proximity to the active plate material. This enhances the efficiency of both discharge and charge cycles. Because of this, and because the internal resistance of the battery is very low they generally charge at a faster rate and to a higher capacity than non-AGM batteries.

Faster charge rate means more amps.

 

 

 

Then the other eyebrow went up at number 8

A 'normal' car alternator will only charge a wet-cell type battery to around 70-80% of its capacity. Because of its higher charging rates an AGM battery will just about fully charge and at a faster rate from the same type of alternator.

Again they are implying that more amps are needed from the electrical system and it is not some special circumstance needed to make it draw more amps.

 

 

 

Then I got to number 9

9. AGM batteries are capable of charging rates up to 75% of their rated ampere hour capacity. In some cases this can lead to damaged alternators or standard auto chargers that may be susceptible to the excessive heat generated when trying to deliver maximum amps.

This is what I was thinking as I was reading this.

In order to charge at a higher rate simply means more amps out of the the stator and the Regulator/rectifier on a bike that already has a marginal system. They are talking about possibly damaging car alternators that have a LOT more power available than out bikes.

 

 

I am going onto the 5th year on my Yuasa, that has never seen a maintainer while it sat in the bike out in a cold steel storage shed thru Wisconsin winters, and was planning to go to an AGM when this one dies. After reading this, I am not so sure now.

 

I wonder how many AGM users have replaced and/or upgraded there stator and/or RR to the higher output ones??? Was it because of the battery and no one ever made the connection?

[OB-1]

I've spent the better part of my adult life working with and teaching about large batteries and complex DC systems that make our modern life possible, so I'd like to clarify some of the statements about AGM batteries. I offer these clarifications to inform our members and in no way mean to disrespect or offend "Saddlebum" or anyone else. My comments are in bold red:

 

Found this on the web. Thought it might be of some interest.

10 Facts about AGM Batteries

1. AGM batteries were originally developed for the military True and so are very robust and can take much more abuse than wet-cell or standard deep-cycle gel batteries.False. Flooded or Deep-Cycle batteries can typically withstand much more user abuse then an AGM battery. As the electrolyte is contained within the glass mats, there is nothing to leak or spill and they are relatively free from freezing damage. True, AGM batteries will survive freezing; however, freezing will reduce their life. BTW: AGM stands for Absorbed Glass Mat. In an AGM battery the traditional separators, (insulators between positive and negative plates within each cell), are replaced with a polymeric fiber mat, (high quality fiberglass). This mat acts as an insulator between the plates and absorbs almost all the electrolyte, (like a sponge). This also immobilizes the electrolyte.

2. As with other sealed batteries there is little to no maintenance with AGMs. Even more of an advantage is that most of them are 'recombinant'. All AGM and Gel-Cell lead-acid batteries are recombinant. What this means is that the oxygen and hydrogen combine inside the battery during charging cycles to form water - hence very little water loss and hydrogen emission. True, under normal operating conditions AGM and Gel-Cell batteries release virtually no hydrogen gas to the atmosphere. These batteries are therefore less hazardous than their counterparts. Well, kinda sorta, but not really. Under the right conditions AGM batteries can vent hydrogen at the same rate as a comparable flooded battery. The immobilized electrolyte in a AGM batteries allows them to be classified as "spill proof" under USDOT standards. This also allows them to still work after being shot. Hopefully this attribute is of no practical use to fellow VentureRiders:shock3:

3. AGM batteries can be stored in otherwise prohibited areas because of their advantages of no leakage and no fumes. This is another of those kinda sorta, but not really statements. Another advantage of this property is that they can be stored on end or on their sides if need be without damage. True, and potentially usefull in other vehicles as you can mount the battery on it's side with no ill effects. Large AGM batteries are typically mounted on their side. Just don't store or mount them up-side-down. They have a pressure relief valve in the top that can leak electrolyte if the valve vents.

4. The battery construction places the electrolyte in closer proximity to the active plate material. This enhances the efficiency of both discharge and charge cycles. False. The electrolyte of all lead-acid cells must be in contact with the active material of the plates for the cell to work. AGM batteries have no advantage over flooded cells in this aspect. Because of this, and because the internal resistance of the battery is very low they generally charge at a faster rate and to a higher capacity than non-AGM batteries. False They can also take heavy discharge rates without damage and can take the occasional discharge below the recommended 50% of capacity rule. False, again.

5. AGMs have a very low discharge rate when stored for extended periods, False. The internal losses of an AGM is essentially the same as a comparable flooded battery.and even if left to totally discharge in storage they can be quickly recharged back to over 95% of their capacity providing they have not been left too long in a discharged state. False. The advantage is, no flat battery after storing for extended periods (within reason of course). False again. All lead-acid batteries have internal losses and AGM's are no better or worse than comparable flooded batteries. The best way to store your motorcycle battery is to ensure it is fully charged and then put it in the refrigerator. Internal losses are affected by state of charge and temperature. Lower temperatures reduce the internal losses. Lower temperatures also reduce available capacity so the battery may not produce much energy until it warms back to room temperature. The standard temperature for automotive batteries is 80F.

6. Under normal operating conditions, a good service life of up to 5 years can be attained. With quality care and handling, managed discharge and charge even longer lifetimes are common. Some reports quote up to 10 years. Kinda, sorta, but not really and not in automotive service. In stationary battery service, the AGM batteries comparable to the one we use in our motorcycles or cars have a claimed 10 year design life. The actual life is typically 3-5 years. Large stationary AGM batteries have a claimed design life of 20 years, but the actual service life is about 10-12 years in ideal operating conditions.

7. AGM batteries are quite a bit more expensive that conventional wet-cell and standard deep cycle. Typically true, but the costs of small AGM batteries are coming down. But if you measure this cost against their robustness, longer life expectancy and better performance, they still present as the best value for money over the longer term. Your money, you decide.

8. A 'normal' car alternator will only charge a wet-cell type battery to around 70-80% of its capacity. Because of its higher charging rates an AGM battery will just about fully charge and at a faster rate from the same type of alternator. False. Todays automotive charging systems are very good and fully capable of fully charging a flooded or AGM battery.

9. AGM batteries are capable of charging rates up to 75% of their rated ampere hour capacity. In some cases this can lead to damaged alternators or standard auto chargers that may be susceptible to the excessive heat generated when trying to deliver maximum amps. The good point though is that AGMs will charge at lesser rates and be quite happy doing that. But, if you are going to spend money on a quality battery then you should really be looking at buying a quality three-stage charger. False. AGM batteries are susceptible to damage from over-charging, but your automotive charging system isn't going to over-charge any battery unless the voltage regulator or computer goes south. However, many home garage type chargers are poorly regulated and can damage an AGM battery.

10. AGM batteries can handle a multitude of roles. They can be used as starting batteries, in deep cycle applications, or as standby batteries for critical powered systems. These reasons make them ideal for camping applications. They can also be connected in series or parallel banks providing for various terminal voltages and ampere capacities. Example: two AGMs can be wired in parallel in a pop-up camper. Charged via a three stage 'Smart' charger and never have an issue with them. Sales hype, all batteries have "issues." Your money, your decision.

[warriorhoneybee]

if ob-1 says it ,it must be true. i know hes one hec of a judi.

[Yammer Dan]

I put a AGM in "Ugly" last fall and put her away in Skid's garage. Started three times since then. On start attempt last week by Skid it was dead. Haven't talked to him yet about how dead. He charged with a 1 amp charger and I started her the next day. Makes me think.. Now I got a headache!!!

[capn eddie]

I installed a odyssey 680 in my 76 gl 1000 goldwing 7 years ago it sat all winter with no charger and it will starts right up . best battery i ever bought and will buy one for my 87VR when it needs a new one. As for the deka i need to know more info and how long will it last. going on 8 years on the odyssey so it would have to out last that to get me to buy one.

[KarlS]

I put a AGM in "Ugly" last fall and put her away in Skid's garage. Started three times since then. On start attempt last week by Skid it was dead. Haven't talked to him yet about how dead. He charged with a 1 amp charger and I started her the next day. Makes me think.. Now I got a headache!!!

 

I installed an AGM from Auto Zone 2 years ago, last winter the bike sat under the awning all winter with just a cover on it and in spring I hit the starter and it fired right up. This winter it sat in a friends garage and last week it started right up again. No battery tenders or charging. I'm very satisfied with my AGM.

[Cougar]

I called a few months back about yuasa batteries, the dealer told me that there now a AGM type. As the lead acid batteries are going away. and the price was $105

[saddlebum]

I've spent the better part of my adult life working with and teaching about large batteries and complex DC systems that make our modern life possible, so I'd like to clarify some of the statements about AGM batteries. I offer these clarifications to inform our members and in no way mean to disrespect or offend "Saddlebum" or anyone else. My comments are in bold red:

 

None Taken. I just found the articale on the internet while researching AGM battaries and felt it worth posting. I myself have no first hand experience with AGM's but am looking into it.

 

I am buying a Deka battery this week. I have a optmate 3 battery charger. Will that work on my new battery.

 

From what I gather as long as it is a 3 stage charger it should be OK. But do not leave it connected to the battery, disconnect charger once battery is fully charged.

 

You know, I love the idea of an AGM too. Now, my first AGM was a Magna Charge off of ebay and it was sold as new but the manufacturer date was about 3 years old. It worked great for the first season, but then went dead over the winter while plugged into a battery maintainer (basic type). I boiled the heck out of it in the spring (nothing to lose) and got it working again for one more season (worked great as long as being used in the bike regularly). Did the same thing again the next winter so just decided to recycle it. Maybe I got a bad one here so I can't say that it it is the norm, but it is a bad experience so just tossing it into the ring. So far I prefer the lead acid with a good maintainer and I get lots of years out of them, at least five and usually more with basic Walmart specials.

 

From what I have been able to understand so far, AGM,s do not fair well on a battery maintainer. They prefer to be fully charged before storage then simply left alone as they apparently have a very low self discharge rate and up to two year shelf life.

Edited March 13, 2012 by saddlebum

[Yammer Dan]

Gonna put my AGM charger on mine and give it 40 amps for a while. See what happens.

[relic]

11. When an AGM battery starts to die it won't charge normally, leaving you looking for a jump at a restaurant in a small town in the middle of nowhere (or right next to it) in Montana.

12. You'll get the system tested at the Yamaha dealer fifty miles down the road and the battery will seem to work just fine.

13. You'll plan on getting a Buckeye stator until you try to start the bike in the spring after keeping it on a Battery Tender all winter, just to have the engine crank once then everything go black.

14. After checking all the fuses you'll go buy a Yuasa lead/acid battery for half the price of the AGM that lasted a year and a half.

15. You'll still consider buying a Buckeye stator since you just aren't sure what happened with that high-price AGM wonder battery.

 

Of course, it could just be me.

 

Not just you. My gell battery after 2 years old and on a tender in a heated garage did the same thing to me on Sunday for the first start of the year. Half crank then all black. No load battery say's 13 volts and charger says fully charged. tried a 12 v light bulb hook up and battery showed 1 volt!!!!! Original lead acid lasted 6 years. I bought the yuasa sealed lead acid yesterday. Maybe the note on not using a full time tender for these batteries has some merit. I am dissapointed and will probably never go Gel again.

[Cdnlouie]

Thanks for the good input on this topic as we start the "battery" season again. I appreciate Saddlebum posting that info which kicked off some good discussion. I also appreciate OB-1 weighing in with his experience in the battery world. I do believe his comments are right on the mark and very reality based. Bear in mind, mine was not a name brand battery a Mega Max (who knows what), so maybe better brands do work great.

 

I would have to concur with other observations that battery maintainers may not be a good idea for the AGM's. Just when you start practicing good battery maintenance practice (ie. maintainers) along comes a curve like this that may indicate they are not so good for all batteries. I can't believe mine died while on a maintainer all winter and it happened for two successive seasons, so that may indicate a relationship.

 

I also found that the AGM started the bike two weeks before it died perfectly, and then it just checked out the next time I went to give it a spring warm-up. The comment that AGM's die fast when they die is perhaps warranted. They are there 100% and then they are not (0%). Not a comforting thought.

 

More research into how to maintain an AGM is definitely needed here. I would suspect they need a controlled steady 14.5 volt charge (not more or not less) on somewhat of a regular basis (like running in the bike) to keep them at primetime. Maybe someone can verify that down the road. And they probably do better with no maintainer and just left alone as a lot of people do (except for the careful ones).

 

I do know that I would not lay (at least some AGM's) in any position except upright as I found that during the unsealing phase of my inquiry into its demise I noticed that the individual cell tops are a rubber cap that does release gas (if overcharged) by expanding the cap until it releases into the air. Also if overcharged the battery will balloon out with the pressure with the potential to explode. The caps don't look completely spill proof to me so I would keep them in the upright position as they are not necessarily a truely sealed unit (at least the brand I had was so).

 

I have upgraded my RR to a Mosfet version which really enhances the charging of a regular lead-acid battery, so I think I will go back to this type as it seems to make the biggest difference to my overall system performance (including upgraded battery cables). I have the original stator and it works just fine with the new RR. It really enhances the low speed charging which improves the starting when hot of the old Ventures. I find that it keeps a lead-acid battery well over 13.0 volts quite easily so I don't see any real advantage of the AGM. Nice idea and it may work great for some fellows, but it seems to be a risky venture money-wise. Like OB-1 said "it's your money."

 

[Snaggletooth]

As I have had such great performance from the DEKA AGM battery but never had a need to charge it in the 4 years it's been in the bike this thread has raised some good issues. I went back to the folks who were kinda of on the front line when we first were looking at the DEKA AGM's about four years back. I contacted Joshua at Bohannon Battery that answered many questions for us back then and even did a load test between the DEKA 18L and the Odessy that was the hot item at the time. That test showed the DEKA had the higher CCA performance that I was looking for.

 

But I sent Joshua the OP on the "facts" and asked about the best charging method for the AGM.

 

This was his response:

 

"To be honest #9 does not make a lot of sense to me. Regardless of whether or not a battery is lead acid or AGM, it should never be "charged" by an alternator. A vehicle alternator is meant to maintain the charge of the battery, but not fully charge a discharged battery. This puts too much strain on the charging system.

 

 

Although certain AGM batteries may be charged at rates up to 75% of their rated capacity, the bottom line is, the faster a battery is charged, the hotter the internals get. We never charge a battery by more than 10% of its rated capacity. This is to ensure a long life span.

 

 

In my opinion the absolute best charger is the Schumacher SE82-6. It has a 6 amp setting for automotive and marine, and a 2 amp setting for lawn and power sport batteries. Its going to charge the battery no matter what the voltage is, and the amps will taper down as the battery charges."

 

 

So to cut that short, the lower charge rate, 2a is the best level to charge a discharged AGM battery. Expecting to quick jump a battery and expect the alternator system to "charge it" may is an issue. Fully charging the battery before reinstalling it in the bike should be method used.

 

I agree on the Schumacher chargers. I have the SSC 1500 with the 2, 10 and 15a settings. I only use the 2a when charging bike batteries. This charger will read a completely discharged battery and bring it back to a full level.

 

Just info guys, not ammo

 

Mike

[Cougar]

Thanks Mike !