Educate me about a AGM battery


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virgilmobile
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Educate me about a AGM battery

Postby virgilmobile » Wed Mar 26, 2014 1:35 pm



I was wondering...Does a AGM battery use a liquid acid like the "old" lead acid battery.The only difference is the acid is suspended in the "absorbed glass mat".?
And is this battery subject to "low liquid level" like I would find in my "old" battery.

I question this because by bike has a standard lead acid battery that needed a bit of "water" to bring the level back up and I also have a small AGM battery on the bike that has gotten poorly.
It's used to power the ignition system while cranking.Now bypassed till I get another battery.
Could it also just be low on "water".



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Ghostman
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Re: Educate me about a AGM battery

Postby Ghostman » Wed Mar 26, 2014 1:43 pm

http://www.bdbatteries.com/batterycomparison.php
Heres a good explanation that hopefully helps.

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Re: Educate me about a AGM battery

Postby themainviking » Wed Mar 26, 2014 2:45 pm

More likely, your AGM battery is sulphated. If you can desulphate it, you may get another couple years out of it. Some chargers, especially those designed for deep cycle batteries, can do this. I have seen it work, and I have seen desulphating short out a battery, so it is sorta a 50/50 proposition.
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Re: Educate me about a AGM battery

Postby virgilmobile » Wed Mar 26, 2014 3:12 pm

Thanks for the details.So it's is a regular lead acid battery.Kinda.
Just no slopping acid,it's held stable by the glass mat.More better design. :D
Sulfating plates is the most likely cause for the demise( low amp capacity) rather than a low acid level.It is a 3 year old battery with a heavy usage life.

Sound right.???

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themainviking
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Re: Educate me about a AGM battery

Postby themainviking » Wed Mar 26, 2014 6:21 pm

Pretty much. The following is from an instructional by a Battery Service Center that I copied and saved a couple of years ago.

Servicing absorbed glass mat (AGM) batteries isn't difficult, but the sophisticated AGM design—which is becoming more popular—does require the proper equipment and a little care.


Here are the key points you should know.


First, look before you leap. When in doubt about the type of battery in a vehicle, always refer to a current battery application guide or accurate parts source.


You may encounter combinations you might never expect, such as a conventional battery under the hood as well as AGM type under the rear seat or inside the trunk of the same car. The underhood battery starts the vehicle while the AGM unit powers, for instance, vital onboard computers.


Second, always replace an AGM battery with the appropriate AGM model. Don't take shortcuts that may cause unexpected complications and shortchange the customer.


Third, never try to add water to any AGM battery. Not only will this maneuver not rejuvenate an AGM battery, it will ruin the unit by exposing its innards to unwanted outside oxygen.


Chemically, outside air poisons the contents of an AGM battery. If you discover that someone else has forced open an AGM battery, replace that battery. Period.


Remember that conventional batteries normally create and then vent off gases to the atmosphere.


To grossly simplify, “gassing” lowers the battery's liquid electrolyte level. Hence, the need to periodically add water to it.


However, AGM batteries literally water themselves by holding and recombining gases that traditional batteries discharge. The AGM format has not eliminated battery gassing completely, but it has reduced gassing to a level that's miniscule compared with that of a conventional battery design.


An AGM battery's low-gassing trait makes it well suited for filling dead space under a car's rear seat or in a corner of its luggage compartment. Besides taking advantage of unused space, this approach also helps by getting the battery out of that extremely harsh underhood environment.


Battery experts explained that an AGM battery has a pressure-relief valve on it and this battery design occasionally may “pass some gas.” What's more, an AGM located under a seat or inside the trunk typically has a vent hose or tube that's supposed to carry any gasses outside the vehicle.


For one thing, always use the correct battery for this kind of application. For another, always reinstall its vent plumbing exactly the way the vehicle manufacturer intended.


Fourth, some technicians favor the familiar load test when diagnosing batteries. Others prefer the simpler conductivity-measuring technique because it doesn't require the finesse and practice that a load test does.


Regardless, battery engineers told me that either technique is adequate for an AGM battery.


Fifth, be sure you've got an up-to-date battery charger that's AGM-capable. You won't regret the investment. Charging an AGM battery is similar to charging a traditional battery, but it's difficult to charge an AGM unit completely—let alone do it quickly—without the appropriate battery charger.


A modern, AGM-capable charger also is better suited to recharging badly discharged AGM batteries than outdated chargers are. Outdated equipment such as those large, roll-about battery chargers may easily raise the voltage of a discharged AGM battery to 16 volts or greater.


Suppose this is the only charger you have handy at the moment.


If so, connect a digital voltmeter to the discharged AGM battery. Then connect the charger to the battery and adjust its output so battery voltage doesn't exceed about 14.5 volts.


Now, you must watch that battery voltage doesn't exceed 14.5 volts; second, the battery cannot overheat. These steps are both inconvenient and time-consuming compared with using a modern, AGM-capable charger.


Finally, remember that battery gasses are both noxious and flammable. So whether you're working on traditional batteries or AGM units, always follow industry-recognized safety precautions—beginning with wearing proper eye protection and keeping potential ignition sources away from all batteries at all times.


During freezing weather, do not attempt to charge any battery that you suspect has frozen. The remnants of electrolyte in a severely discharged battery can freeze in winter weather. Typically, a frozen battery is more than unsalvageable. It's also a potential bomb. Discard it.
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virgilmobile
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Re: Educate me about a AGM battery

Postby virgilmobile » Wed Mar 26, 2014 8:01 pm

Thank You.... :D
I have been educated.much appreciated. :ugeek:

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Re: Educate me about a AGM battery

Postby MNAspencade » Tue Apr 01, 2014 6:39 pm

When charging AGM motorcycle batteries be sure to use a slow 1-2A charge rate. The battery should never get above a warm to the touch state when charging. If it charges too fast the bubbles that form on the plates while charging can lead to burn spots ( the mat prevents the bubbles from freely moving up) and decrease performance. Also after filling a new battery w/acid be sure to let it sit long enough to let any trapped air bubbles work their way up before starting the charging process.

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Re: Educate me about a AGM battery

Postby ct1500 » Tue Apr 01, 2014 9:26 pm

themainviking wrote:Chemically, outside air poisons the contents of an AGM battery. If you discover that someone else has forced open an AGM battery, replace that battery. Period.
Fourth, some technicians favor the familiar load test when diagnosing batteries. Others prefer the simpler conductivity-measuring technique because it doesn't require the finesse and practice that a load test does.
Regardless, battery engineers told me that either technique is adequate for an AGM battery.


Thanks so much for the informative write-up :D

I have a guy bringing in his bike for a going over and one thing he wanted replaced was the battery, OK I said this is what you get (AGM) fully charged from Cyclemax. I had checked the charging voltage previously for him. He calls me last week and said his battery is in but there is a problem. He pulls the caps off and then reads the instructions not to pull caps off until fill, well he didn't fill. I ask where did you get the battery and the reply was XYZ he ordered from to save $8. :roll:

I now know that battery will likely be toast.

What is a simpler conductivity measuring, voltage readings alone?
I always load test batteries because voltage alone does not tell the whole story just the state of charge.


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