Question For AGM Battery Owners...

[MEXICOWANDERER]

Are there folks out there who have decided they do not like AGM batteries and believe their AGM battery purchase was a mistake, and should have purchased standard flooded lead acid batteries instead?

There is a whopper of a price difference amp hour versus amp hour and I am curious to note if anyone at all believes their selection was a mistake. Hopefully positive testimonials will not avalanche the responses, nor will hypothetical dislikes cloud the query...

VALUE is the issue here. Plain and simple...

[MEXICOWANDERER]

Hi BFL13,

Yep. Batteries have changed. The BCI insists all OEMs use same percentage ratio lead/antimony to render a more uniform recycled lead material stockpile. So cyclable batteries as a rule no longer contain 5% antimony. I intend to squeeze RAMCAR and the TJ OEM for the juiciest gossip.

The fluorescent tie / paisley shirt crowd hold nothing sacred. Their sense of organization and propriety is like a fart in a whirlwind.

The OEM converter manufacturer's administration must be a real Rat-eat-rat environment. "Make it sell or grab your walking papers!"

What's waiting in the future?

Soft Start?

Chimes that play the overture to 2001 A Space Odyssey when the converter catches fire?

Odorant that mimics Shaken not Stirred martinis when the charge cycle is complete?

GOD! Am I glad I'm retired!

[BFL13]

"Or, have the lads with the propeller beanies decided to warp bulk and absorbsion into Buzz Words? "

Yes they have. eg, Iota with an IQ4 drops to 14.2v for an eight hour time after doing Bulk to 14.8. It then drops to 13.6 and stays there. They say their Absorption voltage is 14.2. PowerMax does a similar thing except drops straight to 13.6 instead of 14.2 for the Absorption Stage.

Supposedly, they have been told by RV makers to use this "gentle" charging profile because the RV makers think that is what their customers want.

If you don't want that gentle profile because you are not on shore power and want to keep your generator time down, there are several other charger options.

I chose the VEC1093DBD portable charger to solve that and also the PowerMax with the external adjustable voltage. Many inverter/chargers also have adjustable charging profiles to choose if desired. Another choice is the "gizmo" approach.

The WFCO converter has Absorption and Bulk at the same higher voltage 14.4 if you can get it to do Bulk. The PD with Charge Wizard does that with its voltages ok, but it tapers the amps somewhat during Bulk so it takes a bit longer to do a recharge than it should, but it is a reasonable compromise for many folks.

Battery specs have changed in the last few years with increased voltages listed for Vabs. Eg Trojan went from 14.6 to 14.8. This leaves many standard chargers and converters behind that only go to 14.4, which is another "issue" the Rv industry has not addressed very well.

[MEXICOWANDERER]

Bulk is supposed to be at max amperage. The amp number value

Aborbsion occurs when max amps hits voltage limit and must back off to maintain regulation.

Bulk and absorbsion voltage limit is the same exact value.

Or, have the lads with the propeller beanies decided to warp bulk and absorbsion into Buzz Words?

[Wizbangdoodle]

EsoxLucius wrote:

Wizbangdoodle wrote:
So my rv dealer has Fullriver dc224 batteries on sale for $250/ea. I was thinking of picking up 4 of them, but not sure if my charger and inverter are up to the task. i have an Iota charger and a Xantrex 1000w inverter. Will the Iota charge an AGM battery properly? The little I found on their website really doesn't tell me.

That's a pretty good price on those batteries. The Iota IQ4 converter/charger will charge Fullriver AGM batteries adequately with a 14.8 V bulk, 14.2 V absorption, and 13.6 V float regimen.

Good to know, thanks for the info.

[EsoxLucius]

Wizbangdoodle wrote:
So my rv dealer has Fullriver dc224 batteries on sale for $250/ea. I was thinking of picking up 4 of them, but not sure if my charger and inverter are up to the task. i have an Iota charger and a Xantrex 1000w inverter. Will the Iota charge an AGM battery properly? The little I found on their website really doesn't tell me.

That's a pretty good price on those batteries. The Iota IQ4 converter/charger will charge Fullriver AGM batteries adequately with a 14.8 V bulk, 14.2 V absorption, and 13.6 V float regimen.

[MEXICOWANDERER]

Wahhhh!

330 dollars for a 31 Lifeline and 250 dollars for a car plates group 34 that weighs half as much as has plates half as thick...

Something stinks in Peoria...

[greenrvgreen]

I've been using the UPG AGM batts that P Tuna linked, with very good results. While I have no doubt that the Lifeline is a better product (as are similar premium batts), these batteries are about 3 times the cost of the cheapo AGMs. For that kind of price difference I'll take my chances, especially considering the poor treatment I generally give batteries.

As I've said in other threads, I don't believe AGM batts are yet priced for value, even the cheap ones. But I do expect to see this price equation tilt in favor of the AGM, given its far superior useability and the flood of new AGM offerings.

[Wizbangdoodle]

I think I would tend to agree with Mexicowanderer. The specs and procedures are for lab conditions and out in the real world, where you may not be able to hold that tenth of a volt steady, you just have to go with what you've got. I work on industrial electronics all day and what the book says vs what is actually happening can be off, but the equipment keeps on working. Don't sweat it folks.

My question was based on not finding anything on Iota's site that mentions AGM or anything but wet cell batteries. I'm assuming it will work fine.

[pianotuna]

Hi,

Best Converter sells them for $199.00

Amazon $185.00

Wizbangdoodle wrote:
So my rv dealer has Fullriver dc224 batteries on sale for $250/ea. I was thinking of picking up 4 of them, but not sure if my charger and inverter are up to the task. i have an Iota charger and a Xantrex 1000w inverter. Will the Iota charge an AGM battery properly? The little I found on their website really doesn't tell me.

[MEXICOWANDERER]

ARRRRGGGHHHH!

Yet another bunch of "Fal-de -rah" to de-bunk...

TWENTY charging amps per one hundred amp hours of AGM battery is PLENTY. A 55-amp Whiffco with a 36-amp Megawatt is Plenty! This allows a high enough recharge rate to return 100% state of charge within your lifetime. Set the Mega for 14, 4 volts .on a 4- hour timer for 400 A/H worth of AGM. 2-hours for 200 A/H. You can charge an AGM 600 2-hour stints even rhough it doesn't need it AND IT WILL NOT HURT A DARNED THING. Six hundred false 14.4 volt 2-hour recharges. A Megawatt and a timer. Now how hard can that be?

Some of you are needlessly trying to micromanage AGM charging.

There are TENS OF THOUSANDS of AGM batteries out there operating at 14.0+ volts and many of them do it when they are 140 degrees underhood. No, it isn't the best for the battery. But some of you are quibbling over a few tenths of a volt. A Megawatt and a timer will work fine.

When charging via gasoline or diesel gen run time is important THEN pile on the charging amps.

[Wizbangdoodle]

So my rv dealer has Fullriver dc224 batteries on sale for $250/ea. I was thinking of picking up 4 of them, but not sure if my charger and inverter are up to the task. i have an Iota charger and a Xantrex 1000w inverter. Will the Iota charge an AGM battery properly? The little I found on their website really doesn't tell me.

[pnichols]

MEXICOWANDERER wrote:
Concorde Lifeline's PDF file download is pretty much the last-word on care and maintenance of absorbed glass mat batteries. There is no mention of trends and tendencies monitoring using a reliable Amp Hour meter but it general the manual can be trusted, utterly.

I believe that C&D Technologies manufactured the 12 volt Interstate AGM batteries in our RV, so I pretty much use this C&D document as the definitive guide on what to expect from our RV batteries. Go right to the "VRLA Batteries" section. What I especially like is the extensive information in the performance graphs and charts as regarding the charging and maintaining of them with only the stock built-in converter that came with the RV:

http://www.cdtechno.com/resource/support_doc.html

[pnichols]

Mex,

You know my RV battery story - I've posted it several times:

- Two 12 volt 100 amp hour each wheelchair AGM batteries coming up on about 9 years old.

- Their recommended float range is 13.5 volts to 13.8 volts.

- The stock 13.6 volt converter takes care of floating them in storage (RV parked in the back yard).

- The stock 13.6 volt converter and engine alternator take care of charging them on camping trips.

- I dust them off once every 3-4 years.

- I capacity tested them this winter after they had been connected to the converter continuously for weeks ... at which time I considered them as being fully charged (the ammeter also showed zero current going into them). I then put a 20 amp load on them for five hours. At the end of this extended loading, their terminal voltage after several minutes of rest was about 12.1 volts. Unless I'm missing something, this test showed them to still be in "pretty good shape", capacity-wise.

So far, IMHO, AGM RV batteries appear to be both the highest price and the highest value ... of the two battery types.

[full_mosey]

MEXICOWANDERER wrote:
Concorde Lifeline's PDF file download is pretty much the last-word on care and maintenance of absorbed glass mat batteries. There is no mention of trends and tendencies monitoring using a reliable Amp Hour meter but it general the manual can be trusted, utterly.


http://www.lifelinebatteries.com/manual.pdf

X2!

In a nutshell, for a 100AH AGM: charge at 14.3V until charge is 0.5A( 1/2 of 1%) or less. The battery is now ready for use or storage. If stored then switch to 13.3V and float indefinitely. A practical charger would be slightly lower than the battery's AH.

It is best to use a temperature compensating charger that uses a cable to sense the battery temperature since Amps/electrons will warm the AGM. The charger can then adjust the charging/float Volts up for a cold or down for a hot battery. This warming is very slight for AGMs.

I like Magnum PSW inverter/chargers. A cheaper and less efficient charger-only is the 55Amp, $175 Parallax Powermode 4455TC with TempAssure.

Automatic chargers like these that can do a good enough job, but an annual capacity test is needed. My Magnum recently applied 50A for 53 minutes into my 100AH AGM while raising the temp from 67F to 71F. Beforehand, I had run a capacity test that left the AGM at 11.8V resting.

I don't have enough equipment to know what the % capacity of the battery is, but I do know it will do a day's work in a day.

HTH;
John

[MEXICOWANDERER]

Concorde Lifeline's PDF file download is pretty much the last-word on care and maintenance of absorbed glass mat batteries. There is no mention of trends and tendencies monitoring using a reliable Amp Hour meter but it general the manual can be trusted, utterly.


http://www.lifelinebatteries.com/manual.pdf