How long should battery minder take, in conditioning mode?

[Naio]

I've had mine on a 150aH AGM for a couple months now, and it is still blinking.

Battery is not connected to anything else, and was working ok for house loads when I hooked it up, but not recently put to serious test.

[time2roll]

Leave it run. Float/Recondition mode goes indefinitely and will not hurt a bit. Can only help the battery condition.

[profdant139]

I was hoping someone with more knowledge would do the research for me -- I am lazy. But I stumbled onto a useful article:

Pulse rehabs truly dead batteries -- field test

The article is about car batteries, not deep cycle. And it talks about rehabbing a dead battery, not maintaining a good one. And it does not mention AGMs. So there is a lot of wiggle room here. But this article gives me hope that the pulse is not a complete waste of money.

I also did a search for lawsuits involving the Batteryminder that involve claims of fraud. I came up empty. So evidently the plaintiffs' lawyers, who are always on the lookout for class action fodder, have steered clear of this product. Absence of evidence is not necessarily evidence of absence, but in this case it might be.

[MEXICOWANDERER]

Naio, is that blinking light a BLUE blinking light ?

[Almot]

Naio, disconnecting AGM makes sense - IMO - because you don't gain anything by keeping it floating. Float charge is necessary to prevent self-discharge in wet batteries, but AGM don't discharge much. Since nobody knows exactly what is going on inside that sealed black box, this is just my 2 cents.

I keep my AGM floating (and automatic daily 14.6V for a few seconds) because they've developed a huge self-discharge after a year. Must be a lemon from China.

[mlts22]

Anecdotal evidence... it seemed to keep a really torn up 12 volt battery going enough to drive my macerator pump.

As for an AGM battery, I don't see how the pulses can help much, other than minimizing gassing, which isn't an issue. However, FLA, it makes a big difference, due to stratification as well.

[westend]

profdant139 wrote:
Almot, please forgive this foolish question, but why disconnect it? Why not leave the battery on the pulse charge? (This assumes that the pulse function is not harmful to an AGM.)

I'm still hoping that someone really knowledgeable can chime in and tell us authoritatively if the anti-sulphate pulse is nonsense, worse than nonsense, or sense, for both AGMs and wet cells.

(Boy, I really hate this feeling of being ignorant. I am used to being an expert in my narrow field, and it makes me so uncomfortable to be fumbling around in the dark.)

Don't worry, even the engineers of these desulfators are still basically in the dark.
At one time, I met the patent holder of a desulfating battery charger. He had a brochure of 30 or so pages of case studies showing increase in longevity from using his desulfator in fleet based batteries. Yes, I believe the desulfation pulse helps to loosen sulfate from conventional FLA batteries. How much it helps compared to conventional charging schemes, especially those that employ equalization on various schedules, is debatable.
Desulphation circuitry with an AGM battery doesn't make sense to me as the recombinant nature may be skewed and an AGM can actually be left uncharged for an extremely long time without excessive discharge or harm to the battery. I left one 12 V AGM unhooked for 6 months and the SOC had depleted 0.2 DCV during that time.

[profdant139]

Almot, please forgive this foolish question, but why disconnect it? Why not leave the battery on the pulse charge? (This assumes that the pulse function is not harmful to an AGM.)

I'm still hoping that someone really knowledgeable can chime in and tell us authoritatively if the anti-sulphate pulse is nonsense, worse than nonsense, or sense, for both AGMs and wet cells.

(Boy, I really hate this feeling of being ignorant. I am used to being an expert in my narrow field, and it makes me so uncomfortable to be fumbling around in the dark.)

[Almot]

According to the manual, flashing green means that battery is in Float mode, and so is the charger.

I would disconnect it for a few weeks and check self-discharge rate. If it is as slow as your AGM manual says it should be, I would disconnect it for a month or two in winter.

[Naio]

It says 'condition' on the front of the minder, next to the flashing light 🙂

[Almot]

There are no AGM specific chargers or minders. As long as Absorb and Float voltages are what your battery manual requires.

If this https://www.batterystuff.com/files/plus_models.pdf is your charger, I don't see conditioning in the manual. Blinking green light means Float, nothing else. There shouldn't be a daily 15V conditioning stage anyway. Only Concorde battery manuals mention it, and it is not a routine stage, but something you manually from time to time. Mex here considers conditioning aka equalizing necessary with any AGM, so he is probably right.

The difference btw this minder and other float chargers might be that others have only Float stage and no Absorb voltage 14.4. Or only 14.4V and then they shut down. Hard to tell without knowing what "other float chargers".

12117 minder goes daily to 14.4 and then switches to 13.4, this is what one (usually) wants in storage, IF your battery needs preciesely 14.4 and 13.4 (and not 14.6 and 13.3, for example). And if it's 77F. Doesn't look like this 12117 has adjustable setpoints or a temperature compensation, so this is what you have.

[Naio]

Hi, everyone :).

The battery has no brand name on it that I can find, It's not telecom, AFAIK. I bought it used, years ago. Its previous life was in a forklift.

I have not done a conditioning cycle, by ordinary terminology. The battery minder calls its pulse/float thing 'conditioning', which I agree is confusing. I think that's 13.4 volts.

The minder model I have, 12117, was marketed by Northern Tool as good for wet and AGM batteries. It's not the AGM-specific model, but has similar (not identical, off by 0.1-2v IIRC) voltages.

My usual (Noco) charger puts out 14.4v, floats at 13.5.

I think that answers all the questions, express or implied :).

As for my OP, it seems clear that the minder does not distinguish between floating and 'conditioning', and I was wrong to think it did. They are the same thing, as far as it is concerned.

But I am interested in this discussion of whether the minder is actually useful at all, compared to other float devices such as my ordinary charger!

[NinerBikes]

OP should state brand and model of AGM battery. Sounds like a telecom surplus battery she got down where I got mine, but we don't know the brand and model number.

If it's like mine... DEKA brand surplus telecom AGAM, I set the voltage at the Mega Watt at 14.40 volts, with my in line RC charger meter, and let 'er run until the RC line charger shows a current rate at or very close to .75 amps. That specification is a 0.5% rating of the battery amp hour rating at a 20 hour discharge rate. 150 amp hrs x .005 = .75 amp hours current rate is considered fully charged, or close enough.


An AGM does better just disconnected after being fully topped off charged coming back from a camping trip. Discharge rate in fall, winter and spring, are quite low per month. They will require more frequent top charge in the summer, if stored in higher heat. Once a month then is sufficient.

[profdant139]

Almot, maybe we are reading the OP's post a little differently -- I think she said that she has had the AGMs on a Batteryminder for a long while. I am not sure she has done a conditioning or equalizing charge.

The narrow issue is whether the pulse of the BatteryMinder is good or bad for AGMs. The broader issue is whether it is useful for any battery. Certainly, the manufacturer says that it is helpful for many kinds of batteries, and they cite a fair sampling of literature to back up that claim. But I don't know if it has been independently verified.

Meantime, my little black box is blinking away in my garage, and my ordinary group 31s are giving me great service. But that is just anecdotal. As they say, "the plural of anecdote is not data." I am not sure what that means, but it sounds profound.

[Almot]

I don't think OP understands what conditioning is, in case of AGM. After frying them for couple of months it would be odd if they worked at all.

From Lifeline Concorde Manual:

Conditioning (in AGM) should only be done when the battery is showing symptoms of capacity loss due to extended time in a partial or low state of charge condition. This could be caused, for example, by low charging voltage for an extended number of charge cycles, or by repeatedly charging to only 90% state of charge.
NOTE: Some chargers use the term Equalizing Charge instead of Conditioning Charge. An Equalizing Charge is generally applied to flooded lead acid batteries that are susceptible to acid stratification. However, an Equalizing Charge may be used to provide a Conditioning Charge for Lifeline® batteries as described below.
To apply a conditioning charge, first go through the normal charge cycle to bring the battery to full charge. The conditioning charge should then be applied by charging for 8 hours. At 77°F (25°C), the conditioning voltage should be set at 2.58 VPC (15.5 volts )for a 12 volt battery.

[MEXICOWANDERER]

Keep in mind, aviation uses both sealed (recombinant) flooded calcium/calcium and absorbed glass mat batteries. Both must have FAA/PMA certification and the charging system must incorporate an OVL, Over voltage Limiter.