Observation on a new AGM battery.

[Guest]

So for my B'day yesterday, I got a Yusa AGM battery from my daughter. I filled it today and as soon as the acid went in I checked voltage. I don't know why and I expected to get diddly squat. I got 12.67 volts, how could that be Two hours later after 1.5 amp trickle charge, I'm at 15Volts????????? Is any of this normal? I'm used to a fresh regular type battery taking around 6 hours to get better than 13 volts. I'm cornfoozed

Thoughts or observations folks?

Cheers,
spyug

[Dave8338]

Not sure. The AGM's that I have are sealed and those all seem to hold their charge as I've checked them when new and all are 13+ volts, right out of the box.

[Tarbash 27]

Seems perfectly normal to me. I just bought a battery for my friends bike tonight, I filled it and put it on the charger and already had 12+ volts to start with. Now I just have it on the tender so it fully charges before I put it on the bike.

[Billy Ricks]

It's like making a battery out of a lemon, once the acid is introduced it will make power on its own, just not a full charge.

[Steve]

I have never had an AGM that had to be filled.

I know there are "maintenance-free" batteries that are filled once then sealed, but was not aware that some AGM batteries had to be filled.

I do know that AGM batteries tend to have a resting voltage a couple of tenths above "wet" batteries and that they tolerate higher voltages, not sure if that means that they require higher voltage for a full, proper charge.

.

[sparki]

yuasa batteries that i've used in the past come with an acid pack that you use to fill the battery... then "seal for life". so essentially it IS a maintenance free battery... but only after the pack has been added and the filler holes capped

[spyug]

I have never had an AGM that had to be filled.

Good point and I guess I don't have an AGM battery afterall which is what I wanted. Damn and now I can't take it back.

Funny how your mind works ( or doesn't at times). When I was filling it I was thinking that it should have come sealed and ready to go. At least that is how I thought they came. Instead of looking closely at the packaging and instructions for proof of it being AGM I kept on with the task, put it out of my mind and assumed (I guess) that it was the right type. Damn and blast how stupid of me.

In thinking more about it I think the dealer pooched upas well. I had actually ordered it myself a month or more back and my daughter paid for it and picked it up. At the time I asked for an AGM battery and the counter monkey said "What's that?" when I told him he said, "Oh maintenance free" Silly me I again thought we were on the same page.

Well I guess I'm stuck with this one and hopefully it will perform ok.

With the next one, I guess unless its stamped AGM and is fully sealed, I'm not buying.

Drat.

S.

[Steve]

I know it won't help you much right now, Spyug, but here is a bit of explaination from Wikipedia:

VRLA battery

From Wikipedia, the free encyclopedia

A sealed lead-acid battery



VRLA stands for valve-regulated lead-acid and is the designation for low-maintenance lead-acid rechargeable batteries. Because of their construction, VRLA batteries do not require regular addition of water to the cells. VRLA batteries are commonly further classified as:

• Absorbed glass mat battery
• Gel battery

These batteries are often colloquially called sealed lead-acid batteries, but they always include a safety pressure relief valve. As opposed to vented (also called flooded) batteries, a VRLA cannot spill its elecrolyte if it is inverted. Because VRLA batteries use much less electrolyte (battery acid) than traditional lead-acid batteries, they are also occasionally referred to as an "acid-starved" design.
The name "valve regulated" does not wholly describe the technology; these are really "recombinant" batteries, which means that the oxygen evolved at the positive plates will largely recombine with the hydrogen ready to evolve on the negative plates, creating water—thus preventing water loss. The valve is strictly a safety feature in case the rate of hydrogen evolution becomes dangerously high.
One result of this design is a much higher ratio of power to "floorspace" than large, flooded type battery systems; another is a high-rate power capacity, though of relatively short duration. As a result, VRLA batteries are frequently employed in UPS (uninterruptible power supply) or other high-rate applications. Long duration applications such as telecommunications are not as well-suited to VRLA batteries, as there are other, more applicable battery designs available.

Construction

These batteries have a pressure relief valve which will activate when the battery is recharged at high voltage, typically greater than 2.30 volts per cell. (A 12 volt battery has six cells.) Valve activation allows some of the active material to escape thus decreasing the overall capacity of the battery.The lids (covers) typically have gas diffusers built into them that allow safe dispersal of any excess hydrogen that may be formed during overcharge. They are not permanently sealed, but are maintenance free; and they can be oriented in any manner, unlike normal lead-acid batteries which must be kept upright to avoid acid spills and to keep the plates' orientation vertical.
At high currents, electrolysis of water occurs, expelling hydrogen and oxygen gas through the battery's valves. Care must be taken to prevent short circuits and rapid charging. Charging with a constant voltage (called the float charge voltage; 2.26 V per cell for a lead-acid chemistry) can cause a rapid initial current, so therefore it is suggested to begin with a constant current, using constant voltage only for the final portion of the charging. However, the float charge voltage should not be exceeded by much for typical usage, so the switch between the two modes typically occurs when the float voltage is needed to sustain the charging current through the battery's internal resistance (as per Ohm's Law). The easiest way to implement this is to use a constant voltage device with a current limiter.
Comparison with flooded lead-acid cells

Compared with flooded lead-acid cells, VRLA batteries offer several advantages. The battery can be mounted in any position, since the valves only operate on over pressure faults. Since the battery system is designed to be recombinant and eliminate the emission of gases on overcharge, room ventilation requirements are reduced and no acid fume is emitted during normal operation. The volume of free electrolyte that could be released on damage to the case or venting is very small. There is no need (nor possibility) to check the level of electrolyte or to top up water lost due to electrolysis, reducing inspection and maintenance.

Absorbent glass mat (AGM)

Absorbent glass mat (AGM) is a class of VRLA battery in which the electrolyte is absorbed into a mat of fine glass fibers. The plates in an AGM battery may be flat like a wet cell lead-acid battery in a rectangular case. In cylindrical AGMs, the plates are thin and wound, like most consumer disposable and rechargeable cells, into spirals so they are also sometimes referred to as spiral wound. Their unique (for lead-acid chemistries) construction also allows for the lead in their plates to be purer as they no longer need to support their own weight as in traditional cells. Their internal resistance is lower than traditional cells due to plate peroximity and the pure lead plates have lower resistivity, they handle higher temperatures better, and self-discharge more slowly.

Their specific power is very good and they can be charged and discharged quite rapidly, however their specific energy tends to be lower than traditional flooded batteries. They are often used in high performance electric vehicles due to their high power density.

Gel battery


A gel battery (also known as a "gel cell") is a VRLA battery with a gelified electrolyte; the sulfuric acid is mixed with silica fume, which makes the resulting mass gel-like and immobile. Unlike a traditional wet-cell lead-acid battery, these batteries do not need to be kept upright (though they cannot be charged inverted). In addition, gel batteries virtually eliminate the electrolyte evaporation, spillage (and subsequent corrosion issues) common to the wet-cell battery, and boast greater resistance to extreme temperatures, shock, and vibration. These batteries are often colloquially referred to as sealed lead-acid (SLA) batteries due to their non-leaking containers, but they are not completely sealed; the valve regulation system allows for gas to be expelled. Chemically they are the same as wet (non-sealed) batteries except that the antimony in the lead plates is replaced by calcium. This preserves the mechanical characteristics but renders the construction far less prone to gassing. The battery type is often referred to as a lead-calcium battery.

Applications

Many modern motorcycles on the market utilize AGM or factory-sealed AGM batteries for the combined benefits of reduced likelihood of acid spilling during accidents, and for packaging reasons (lighter, smaller battery to do the same job; the battery can be installed at an odd angle if needed for the design of the motorcycle).
Due to the higher manufacturing costs compared with flooded lead-acid batteries, AGM technology is currently being used on premium vehicles. As vehicles become heavier and equipped with greater electronic devices such as navigation, stabilitiy control, and premium stereos, AGM batteries are being employed to lower vehicle weight and provide better electrical reliability compared with flooded lead-acid batteries.
New 5 series BMWs from March 2007 incorporate AGM batteries in conjunction with devices for recovering brake energy using regenerative braking and computer control to ensure the alternator charges the battery when the car is decelerating.
Vehicles used in auto racing may use AGM batteries due to their vibration resistance.
Deep-cycle AGMs are also commonly used in large-scale amateur robotics. Two examples are the FIRST and IGVC competitions.
AGM batteries are routinely chosen for remote sensors such as ice monitoring stations in the Arctic. AGM batteries due to their lack of free electrolyte will not crack and leak in these cold environments.
Gel cell batteries are used extensively in power wheelchairs, as the extremely low gas and acid output makes them much safer for indoor use.
SLA "Gel" cells are also the standard power source in sailplanes, due to their ability to withstand a variety of flight attitudes and a relatively large ambient temperature range with no adverse effects.

[spyug]

Thank you Steve. Now I'm more confused but hey that's my normal state anyway.

That's a very good article and does a good job of detailing the differing types. I guess to a lot of us and probably the dealers too, they just lump everything under the one title of "maintenace free" and leave it at that.

Bottom line is performance, so as long as it takes and holds a charge and gives me a fair life I'll be happy.

The battery was for the new Kat project but since its not yet ready to go and they are calling for sunny 10Celsius on Sturday and Sunday, I'll need to "road test"it in the GS First ride of the new season.....yeah!!!

Thanks for clearing that up for me sir.....you are ( and I've said this before) a fount of knowledge and an all round good guy.

Cheers,
spyug

[Theo]

Maybe you don't have an AGM but if you are saying that just because you had to fill it, you might be mistaken. I recently bought an AGM battery that came with the liquid separate and had to fill it up. The instructions said to wait for a few hours while the mats absorb the fluid before putting it on the charger. Like sparki said earlier, some AGM batteries need to be filled before put into service. Or you are right, and this battery you got is not an AGM battery. Just a couple of cents.

Good point and I guess I don't have an AGM battery afterall which is what I wanted. Damn and now I can't take it back.

Funny how your mind works ( or doesn't at times). When I was filling it I was thinking that it should have come sealed and ready to go. At least that is how I thought they came. Instead of looking closely at the packaging and instructions for proof of it being AGM I kept on with the task, put it out of my mind and assumed (I guess) that it was the right type. Damn and blast how stupid of me.

In thinking more about it I think the dealer pooched upas well. I had actually ordered it myself a month or more back and my daughter paid for it and picked it up. At the time I asked for an AGM battery and the counter monkey said "What's that?" when I told him he said, "Oh maintenance free" Silly me I again thought we were on the same page.

Well I guess I'm stuck with this one and hopefully it will perform ok.

With the next one, I guess unless its stamped AGM and is fully sealed, I'm not buying.

Drat.

S.

[Mysuzyq]

Good point and I guess I don't have an AGM battery afterall which is what I wanted. Damn and now I can't take it back.

With the next one, I guess unless its stamped AGM and is fully sealed, I'm not buying.
Drat.
S.

Don't worry. AFAIK, all Yuasa AGM (probably other brands as well) have to be filled with the enclosed acid packs.....only difference is whether you do this, or it is done at the point of sale. I ordered mine over the phone from Cycle World, and expressed the same surprise, when the tech said they would have my battery 'filled and ready' for pick up the next morning. They are true maintenance-free AGMs once sealed, and generally, you can expect pretty good performance and longevity from the Yuasa.
Tony.

[bakalorz]

Thank you Steve. Now I'm more confused but hey that's my normal state anyway.

That's a very good article and does a good job of detailing the differing types. I guess to a lot of us and probably the dealers too, they just lump everything under the one title of "maintenace free" and leave it at that.

Bottom line is performance, so as long as it takes and holds a charge and gives me a fair life I'll be happy.

The battery was for the new Kat project but since its not yet ready to go and they are calling for sunny 10Celsius on Sturday and Sunday, I'll need to "road test"it in the GS First ride of the new season.....yeah!!!

Thanks for clearing that up for me sir.....you are ( and I've said this before) a fount of knowledge and an all round good guy.

Cheers,
spyug

According to Yuasa's Battery tech manual, at least some of their AGMs do come with acid to add.

The amount of acid added to each cell is critical, so the primary difference is that the acid is in a "6-pack" where each cell gets its own little bottle of acid, and ALL the acid from that bottle goes in the cell.

Normal and low maint batteries come with one bottle which you add some of to each cell, and have some left over.

Which kind of acid did you get ?

Also, the type of battery is MUCH less important than the health of the charging system.
The cheapest battery from wal-mart with a good charging system will give years of service.
The best most expensive battery you can buy with a marginal charging system will be dead in months, weeks, or even days.

There are some advantages to AGM, but its not THAT big a deal.
Smaller/lighter for a given capacity,
Won't spill if tipped over,
1/3 slower self-discharge,
No need to add water.

Thats it ...

[pontiacstogo]

There are some advantages to AGM, but its not THAT big a deal.

Is to me - I have four bikes all with AGM's and I think they're the best think since sliced bread. I bought my first one in 2004 and it's still going strong. I love not having to dick with chargers or battery tenders. In fact, I've only ever had to charge one of them, and that's only because I left they key on for a couple of hours. I like that I can just leave them in the bikes during the winter months, and not have to remove them or top them or anything else (particularly on the Kat cause that battery is buried in there).

I buy the Big Crank AGM (Deka) brand from Batterymart and they come sealed and charged - ready to go out of the box.

[waterman]

I have purchased two Yuasa batteries for my KLX. Both were called sealed AGMs and I had to fill both of them. It was easier to fill then the typical wet flooded cell cheepo Walmart battery since it had 6 individual bottles ganged together as opposed to the single bottle of acid with hose arrangement. In the AGM, you simply remove foil from bottles and insert into holes on battery and invert. It is easier to hold battery upside down on top of bottles and then invert them together. With the single bottle, I always had extra acid to discard, not so with the AGM.

Then you let battery set for a time and then apply the sealing strip to contain the acid. A quick routine charge will bring it to full charge and away you go.

I think the advantage to filling it yourself is that you are guaranteed a fresh battery for maximum life. I believe all batteries degrade from the minute they are filled. If the typical filled wet cell battery is sitting on the shelf of a store for a year, then it will have lost a year of potential life.

FWIW, I got 6 years of life out of first AGM for Klx, still working on second. I have been using cheap flooded Walmart batteries in Suzukis, getting about 3 years on average. May go to AGM for Suzuki this year to see if any difference in performance.

[Mysuzyq]

I have purchased two Yuasa batteries for my KLX.
I think the advantage to filling it yourself is that you are guaranteed a fresh battery for maximum life. I believe all batteries degrade from the minute they are filled. If the typical filled wet cell battery is sitting on the shelf of a store for a year, then it will have lost a year of potential life.

I was guessing this to be the reason behind it too....they have an indefinite shelf life till filled. I'm entering my 5th season with the same Yuasa AGM, so pretty satisfied with it's longevity, even if I change it sometime soon....but Pontiactogo's 6 year AGM is pretty impressive, without any external charging.