volts
- Thread starter 05chop
- Start date
Nomad2day
Longhair Redneck Geek
Kinda got my interest up when you asked the question. He is a quote from a website. Mo difference from a regular battery in charging.
http://www.windsun.com/Batteries/Battery_FAQ.htm#Major%20Battery%20Types
AGM, or Absorbed Glass Mat Batteries
A newer type of sealed battery uses "Absorbed Glass Mats", or AGM between the plates. This is a very fine fiber Boron-Silicate glass mat. These type of batteries have all the advantages of gelled, but can take much more abuse. We sell the Concorde (and Lifeline, made by Concorde) AGM batteries. These are also called "starved electrolyte", as the mat is about 95% saturated rather than fully soaked. That also means that they will not leak acid even if broken.
AGM batteries have several advantages over both gelled and flooded, at about the same cost as gelled:
Since all the electrolyte (acid) is contained in the glass mats, they cannot spill, even if broken. This also means that since they are non-hazardous, the shipping costs are lower. In addition, since there is no liquid to freeze and expand, they are practically immune from freezing damage.
Nearly all AGM batteries are "recombinant" - what that means is that the Oxygen and Hydrogen recombine INSIDE the battery. These use gas phase transfer of oxygen to the negative plates to recombine them back into water while charging and prevent the loss of water through electrolysis. The recombining is typically 99+% efficient, so almost no water is lost.
The charging voltages are the same as for any standard battery - no need for any special adjustments or problems with incompatible chargers or charge controls. And, since the internal resistance is extremely low, there is almost no heating of the battery even under heavy charge and discharge currents. The Concorde (and most AGM) batteries have no charge or discharge current limits.
AGM's have a very low self-discharge - from 1% to 3% per month is usual. This means that they can sit in storage for much longer periods without charging than standard batteries. The Concorde batteries can be almost fully recharged (95% or better) even after 30 days of being totally discharged.
AGM's do not have any liquid to spill, and even under severe overcharge conditions hydrogen emission is far below the 4% max specified for aircraft and enclosed spaces. The plates in AGM's are tightly packed and rigidly mounted, and will withstand shock and vibration better than any standard battery.
Even with all the advantages listed above, there is still a place for the standard flooded deep cycle battery. AGM's will cost 2 to 3 times as much as flooded batteries of the same capacity. In many installations, where the batteries are set in an area where you don't have to worry about fumes or leakage, a standard or industrial deep cycle is a better economic choice. AGM batteries main advantages are no maintenance, completely sealed against fumes, Hydrogen, or leakage, non-spilling even if they are broken, and can survive most freezes. Not everyone needs these features.
Neil
http://www.windsun.com/Batteries/Battery_FAQ.htm#Major%20Battery%20Types
AGM, or Absorbed Glass Mat Batteries
A newer type of sealed battery uses "Absorbed Glass Mats", or AGM between the plates. This is a very fine fiber Boron-Silicate glass mat. These type of batteries have all the advantages of gelled, but can take much more abuse. We sell the Concorde (and Lifeline, made by Concorde) AGM batteries. These are also called "starved electrolyte", as the mat is about 95% saturated rather than fully soaked. That also means that they will not leak acid even if broken.
AGM batteries have several advantages over both gelled and flooded, at about the same cost as gelled:
Since all the electrolyte (acid) is contained in the glass mats, they cannot spill, even if broken. This also means that since they are non-hazardous, the shipping costs are lower. In addition, since there is no liquid to freeze and expand, they are practically immune from freezing damage.
Nearly all AGM batteries are "recombinant" - what that means is that the Oxygen and Hydrogen recombine INSIDE the battery. These use gas phase transfer of oxygen to the negative plates to recombine them back into water while charging and prevent the loss of water through electrolysis. The recombining is typically 99+% efficient, so almost no water is lost.
The charging voltages are the same as for any standard battery - no need for any special adjustments or problems with incompatible chargers or charge controls. And, since the internal resistance is extremely low, there is almost no heating of the battery even under heavy charge and discharge currents. The Concorde (and most AGM) batteries have no charge or discharge current limits.
AGM's have a very low self-discharge - from 1% to 3% per month is usual. This means that they can sit in storage for much longer periods without charging than standard batteries. The Concorde batteries can be almost fully recharged (95% or better) even after 30 days of being totally discharged.
AGM's do not have any liquid to spill, and even under severe overcharge conditions hydrogen emission is far below the 4% max specified for aircraft and enclosed spaces. The plates in AGM's are tightly packed and rigidly mounted, and will withstand shock and vibration better than any standard battery.
Even with all the advantages listed above, there is still a place for the standard flooded deep cycle battery. AGM's will cost 2 to 3 times as much as flooded batteries of the same capacity. In many installations, where the batteries are set in an area where you don't have to worry about fumes or leakage, a standard or industrial deep cycle is a better economic choice. AGM batteries main advantages are no maintenance, completely sealed against fumes, Hydrogen, or leakage, non-spilling even if they are broken, and can survive most freezes. Not everyone needs these features.
Neil
05chop
Well-Known Member
Neil the reason i asked is i bought a new battery charger.it has four setting,normal battery,deep cycle,agm,6volt.this charger has a volt meter on it.when charging a normal lead acid battery the volts go as high as 14.95.with the deep cycle and agm its never any higher than 13.50.my question is in my truck when its running its charge rate with the agm batterys is at 14.50-14.80.Even in the instuction manuel its says no more than 13.50 volts for any agm battery when charging.the voltage regulator isnt set that low on my truck or any other truck i own. 05chop
Nomad2day
Longhair Redneck Geek
Now I understand why somewhat.
I have read in some places that it does not matter and others say it does.
It appears voltages higher that about 14vdc wrack havoc on them and lead them to a early failure. Heat is a big player on them also. Seems like they are awesome storage type batteries for RV's and marine applications and that is why the newer chargers have a special setting on them. You can purchase a external voltage regulator to adjust the output on your truck if you wanted.
http://www.rversonline.org/ArtAGM.html
That First Important Step
There is a lot of interest in high-tech batteries these days. While Valve Regulated Batteries possess many traits and characteristics that seemingly make them a desirable replacement for standard (flooded) lead acid batteries, care must be taken to insure that they are not subjected to environmental and operational abuse that would dramatically shorten their life span. Valve regulated batteries are expensive, sometimes double or even treble the cost of standard RV deep-cycle batteries.
CHARGING VOLTAGE VALUE IS CRITICAL
AGM and Gelled batteries require a charging voltage that does not exceed 14.00 volts (summer temperatures may require even lower voltages). Unfortunately almost all automotive charging systems have a permanently fixed set point voltage that exceeds 14.00 and this spells trouble. Subjecting the batteries to (commonly found) 14.6 volts for a prolonged period will eventually destroy them. Pusher diesel motorhomes normally use truck-type alternators and voltage regulators and most have internal set screws which can be fine-tuned (To lower the voltage set point). Automobiles (pickup trucks) and standard motorhome charging systems can be modified to accept an exterior adjustable voltage regulator. Your local automotive electrical rebuild shop can be a lifesaver if you elect to go that route. For your edification, 14.05 volts is my personal "upper limit" for charging valve regulated batteries.
THERMAL RUNAWAY
The name "thermal runaway" sounds ominous and when it happens to an Absorptive Glass Mat battery the results can be dramatic. A curious electro chemical reaction can take place inside an "AGM" battery if it is overheated while being charged. The phenomenon can be the result of too high a charging voltage, which will overheat any battery, too high an environmental temperature or a combination of both elements. Instead of tapering off, the charging current actually increases as the battery temperature increases. In extreme cases the electrolyte and binder material can be forcibly ejected from the battery vents. Obviously the battery will be destroyed. The point here is to pay attention to the battery's location and charging voltage limit.
MODERATE TEMPERATURE ENVIRONMENT
Both gelled electrolyte and AGM batteries insist on being located in an environment well away from high underhood engine or radiator temperatures. As a matter of fact the manufacturers of these types of batteries insist that all charging must cease altogether if the core of the battery reaches one hundred twenty degrees Fahrenheit. This point becomes critical in some pusher diesel bus applications that fit the house batteries in the path of radiator exhaust heat!
DON'T FORGET THOSE "OTHER" CHARGING SOURCES
When fitting valve regulated batteries to an RV care must be exercised to insure that the vehicle converter or battery charge finishing voltage does not exceed the 14.00 Volt limit. Solar voltaic charging systems must have a voltage regulator (commonly referred to as a "controller"). Auxiliary generators with integral charging systems must have their charging systems adjusted or defeated. And finally the owner of the Valve Regulated Battery must understand that even one unsupervised service station "quick-charge" will destroy even the best maintained gelled or AGM battery.
I have a friend that works at battieries plus and I will run this by him to see what he says.
Neil
I have read in some places that it does not matter and others say it does.
It appears voltages higher that about 14vdc wrack havoc on them and lead them to a early failure. Heat is a big player on them also. Seems like they are awesome storage type batteries for RV's and marine applications and that is why the newer chargers have a special setting on them. You can purchase a external voltage regulator to adjust the output on your truck if you wanted.
http://www.rversonline.org/ArtAGM.html
That First Important Step
There is a lot of interest in high-tech batteries these days. While Valve Regulated Batteries possess many traits and characteristics that seemingly make them a desirable replacement for standard (flooded) lead acid batteries, care must be taken to insure that they are not subjected to environmental and operational abuse that would dramatically shorten their life span. Valve regulated batteries are expensive, sometimes double or even treble the cost of standard RV deep-cycle batteries.
CHARGING VOLTAGE VALUE IS CRITICAL
AGM and Gelled batteries require a charging voltage that does not exceed 14.00 volts (summer temperatures may require even lower voltages). Unfortunately almost all automotive charging systems have a permanently fixed set point voltage that exceeds 14.00 and this spells trouble. Subjecting the batteries to (commonly found) 14.6 volts for a prolonged period will eventually destroy them. Pusher diesel motorhomes normally use truck-type alternators and voltage regulators and most have internal set screws which can be fine-tuned (To lower the voltage set point). Automobiles (pickup trucks) and standard motorhome charging systems can be modified to accept an exterior adjustable voltage regulator. Your local automotive electrical rebuild shop can be a lifesaver if you elect to go that route. For your edification, 14.05 volts is my personal "upper limit" for charging valve regulated batteries.
THERMAL RUNAWAY
The name "thermal runaway" sounds ominous and when it happens to an Absorptive Glass Mat battery the results can be dramatic. A curious electro chemical reaction can take place inside an "AGM" battery if it is overheated while being charged. The phenomenon can be the result of too high a charging voltage, which will overheat any battery, too high an environmental temperature or a combination of both elements. Instead of tapering off, the charging current actually increases as the battery temperature increases. In extreme cases the electrolyte and binder material can be forcibly ejected from the battery vents. Obviously the battery will be destroyed. The point here is to pay attention to the battery's location and charging voltage limit.
MODERATE TEMPERATURE ENVIRONMENT
Both gelled electrolyte and AGM batteries insist on being located in an environment well away from high underhood engine or radiator temperatures. As a matter of fact the manufacturers of these types of batteries insist that all charging must cease altogether if the core of the battery reaches one hundred twenty degrees Fahrenheit. This point becomes critical in some pusher diesel bus applications that fit the house batteries in the path of radiator exhaust heat!
DON'T FORGET THOSE "OTHER" CHARGING SOURCES
When fitting valve regulated batteries to an RV care must be exercised to insure that the vehicle converter or battery charge finishing voltage does not exceed the 14.00 Volt limit. Solar voltaic charging systems must have a voltage regulator (commonly referred to as a "controller"). Auxiliary generators with integral charging systems must have their charging systems adjusted or defeated. And finally the owner of the Valve Regulated Battery must understand that even one unsupervised service station "quick-charge" will destroy even the best maintained gelled or AGM battery.
I have a friend that works at battieries plus and I will run this by him to see what he says.
Neil
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Shit Nomad!! You had this problem right, I think I remember from the other site??
05chop
Well-Known Member
NEIL They sure dont tell you this when you go to buy a new battery.I put three optima batterys in my powerstroke.Extra battery for winch inside bed of truck.AGM batterys I though where the best.I have one in my chopper now. didnt realize that high volts ruins them 14 plus volts.thanks neil 05chop
