Battery Desulfators- Do they work?

Originally Posted By: ImpactBattery
Originally Posted By: JHZR2
Originally Posted By: 3311

Doesn't matter if the AGM, Gel or Flooded. The recharging process is the same.

Now if this is a trickle charger with a fancy name, that would work well, as others have said. Trickle charging, if you have the time is better because can avoid damaging a battery over gassing caused by high voltage and heat.



The process (e.g. CC/CV) may be the same, but the max charge voltage anf float voltages differ between gel, flooded and AGM, with the voltage increasing respectively.

Recombination kinetics generally occur at a rate to sufficiently allow C/3 charging. For a 60Ah battery, that means 20A. On bigger batteries like 49, 94, etc., 8A is roughly C/10. So generally most commonly available battery chargers will not create a thermal issue. There is a TON of thermal mass. Ambient will do more for degrading batteries.

On occasion, the high voltage is beneficial for equalization and for removal of sulfate. The means of removing sulfate is by presence of a high voltage charge, which causes gassing, which is why it is not desirable. The desulfation processes give a higher voltage for a short amount of time in a cyclic basis, so the time averaged gas generation is low enough to allow recombination.

To me, the most important thing is temperature compensation, as the voltage range in an area like the NE where we have four solid seasons is over 1.5V depending upon ambient temperature. Most cheap junior and HF type chargers dont temperature compensate. So they overcharge above roughly 75F, and undercharge below, like in the winter when it is more important. The lower the SOC, the higher the freezing point of the electrolyte. It doesnt take much to get the freezing point into the 20-27F range...


You are obviously a smart guy, but I am curious as to why you think the presence of a high voltage charge is the only way to remove sulfate crystals? High voltage charges can actually mess with vehicle electronics, harm batteries if not compensated for and was the basic method used in the 50's (yes the delivery method has been adjusted). Frequency pulsing dissolves the crystals and causes no excessive heat. I have yet to see an Xtreme charger over charge any battery. The microprocessor inside does all the work and since voltage never spikes above 14.8V and the unit continually tests the battery it cannot overcharge a battery.

The Battery Minder desulphating chargers that use both frequency based pulsing and voltage pulsing require a temperature compensation control (i.e. model BM12248) because they can overcharge based on ambient temperatures. That is solely due to the voltage spikes that average 18-22V, but I have been told can reach into the 40V range. These chargers work pretty good and would be #2 on my list behind PulseTech chargers. [We do not even consider CTEK a desulphating charger. Several years ago we pointed out our findings to them and they purchased some of the competition’s chargers to compare results…a couple months later we got the cold shoulder and the president of the company never replied to us again. We were hoping they would prove us wrong and send a detail comparison chart, but I guess the lack thereof indicates they did not stand up well to the head to head competition.]


I am interested in your comments of seeing 18-22V or 40V. I have not seen this, I have seen excursions in the 14-15V range, fluctuating, when under float, which is roughly 13.4V. Maybe the voltage spikes are higher and the sampling rate on my Fluke doesnt show it, but Ive not seen it.

Sulfate can be dissolved in the 2.5-2.66V per cell range. That is the 15-16V range. There is no basis I know of to justify 18, 22 or 40V. All it would do is instantly electrolyze some water if the current was high enough, or else bunch current and create a localized concentration overpotential someplace.

I agree if a charger is putting voltages like that out, there is a problem. Ive just not seen it...
 
Or have I? I bought a giant group 95 battery last year, and a battery minder 12117 this past summer. I put the minder onto the battery, which I had bought for a project that I never got around to, at thanksgiving.

Now remember that it is cold in nj and this charger is not temperature compensated so it should technically leave the battery slightly undercharged. The charger is rated at 1.33A.

I was changing cars tonight and was in the garage and checked out the battery. I noticed some residue on the terminal!

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it is a white color, perhaps lead oxide. I never used dielectric grease to coat the terminals. The terminal at the casing looks clean. No sign of acid coming out.

But look at the positive connection:

9009E938-F151-4A07-BF21-248F6D73C53A-5443-0000092E99D6B3A0_zps533d29b9.jpg


And the negative was the same way!

00DB8B6F-CB53-401E-A0FD-1F9329810AB6-5443-0000092E95924718_zps02eaa161.jpg


The battery is on a metal shelf, FWIW.

81BEF86C-259A-40C1-A2EB-952F3EBF3AEE-5443-0000092E9DEFD56E_zps1446c75b.jpg


But that rusting of the clamps and discoloration of the terminals bothers me... Wonder if it has to do with the desulation voltage excursions...

Are battery chargers with clamps supposed to NOT be affixed to the battery terminals? I ask because a year or two ago, I had a maintainer on a group 4 battery that was maybe 8-10 years old, and one day I went out and one clamp was completely dissolved. I chalked it up to an old battery, but maybe not. I dont recall if i had it on a battery tender or minder, though i think it was a Minder.
 
I could be way off base but I wonder if the corrosion seen on the charging clamps is not just due to corrosive outgassing on the clamps that are not well plated.
 
It almost seems like a poor terminal to casing seal, and corrosive gas is causing the issues you see on the terminal and clamp. I also notice you didn't open the fill caps on the battery. If the small vent valve is plugged, you will have a pressure buildup inside the battery.
 
I'm sure I did something wrong.... I didn't put dielectric grease on the terminals first. That tends to help keep everything clean and closed.

I didn't open vents because this is long term maintenance storage on a 1.33A max, multi-stage charger. The current going through was likely less than 50mA. The battery is in the state as it would be installed in a vehicle with its alternator at 14.7V, while this was floating at 13.4.

The terminals were clean, beautiful and unused. But I think that the super tiny contact area on clamps may have something to do with it. Especially if it is taking the float voltage real high.

I'm going to open up discussions with battery minder about this.

My main concern is vehicle electronics and corrosion of vehicle cables. Perhaps those points are moot - there may be some expectation of cable impedance in the charger designs, which this setup didn't have...
 
vasoline works good but that deposit is lead sulfate and there is some gassing going on there. The plating on those clamps is no way acid resistant.
 
Originally Posted By: JHZR2
Or have I? I bought a giant group 95 battery last year, and a battery minder 12117 this past summer. I put the minder onto the battery, which I had bought for a project that I never got around to, at thanksgiving.

OT: I could not find the specs for group 95, only group 95R. Are you sure it's group 95 ?

Of all dimensions, group 95R is longer than group 49 by 1/2". It should fit my E430.
 
95R, Sorry. Bought it for my diesel which also takes a 49. Havent messed with trying a swap, which is why it has been sitting on a charger...

A 95R has the terminals on the same sides as a 49, which is not an 'R' battery...
 
Thanks. I will look into 95R when I need to replace the current 49.

We don't have AAP here in CA, I don't remember ever saw 95R at other chains.
 
I have yet to verify that it will fit in a 49 spot. I like the 95 from aap because it has real vent caps and an eye on it.
 
This topic interests me. I may come across older batteries on some cars I look at when that time comes. Can someone please share how to overcome a surface charge on a battery that may very well be a few years old and have been hooked up to nothing but the car's alternator its whole life?

Also I see a lot of batteries with fine white powder-like substance on their tops, and it only increasses after a good charging with a normal charge be it pulse smart or non, what does that mean?
 
I wish I could agree, but I cannot do so. I know all the metrics and have questioned them myself since the advent of ultra-smart chargers. I read many articles saying 12.5-12.8 is fully charged. I have yet found an AGM battery arrive from the factory that low. In fact they get that low for at least a year sitting on a shelf.

Surface voltage will disappear in hours and the battery will settle to its true charged voltage. I have seen with my own eyes several brands of chargers that leave 12V batteries between 13-13.2V for weeks. Just like when they arrive direct from the factory (which is a six week journey from China). I cannot call that surface voltage, which should dissipate in hours or when loaded.
 
AGM sealed batteries have a higher end point for the specific gravity of the electrolyte. The AGMs will be around 1.310 sg whereas a flooded wet cell would be around 1.285 sg. This is what gives them the higher OCV.
 
Quote:

I am interested in your comments of seeing 18-22V or 40V. I have not seen this, I have seen excursions in the 14-15V range, fluctuating, when under float, which is roughly 13.4V. Maybe the voltage spikes are higher and the sampling rate on my Fluke doesnt show it, but Ive not seen it.

Sulfate can be dissolved in the 2.5-2.66V per cell range. That is the 15-16V range. There is no basis I know of to justify 18, 22 or 40V. All it would do is instantly electrolyze some water if the current was high enough, or else bunch current and create a localized concentration overpotential someplace.

I agree if a charger is putting voltages like that out, there is a problem. Ive just not seen it...


The tech I spoke with at Battery Minder about a week and half ago indicated to me that their chargers rapidly spike to around 20V. This is happening in micro seconds and would be hard to measure without computerized equipment. I have read some product sites that their units have a max voltage of 40V. That scares me! One would have to think this would need to be regulated and is only capable of such voltage and does not actually put out voltage that high. I do not have firsthand experience on those types of units. Only Battery Minder, CTEK, Genius, MotoBatt, Schauer, Dual Pro...etc
 
I've used a BatteryMinder 12248 on some heavily cycled deep cycle batteries on numerous occassions.

The charger works nicely to top charge and maintenance charge, but I noticed no improvements in battery performance after keeping it on the heavily cycled batteries for a week and more. Perhaps on a battery which was allowed to slowly sulfate though self discharge, a pulse type desulfator would be more effective.

The battery minder is my friend's. He bought it hoping to magically restore some batteries he killed by thinking batteries have unlimited shelf lives. He tried really hard to bring those batteries back to life, fruitlessly.

Some people apparently think a charger can magically restore the depleted plates within a battery. Better off just pouring some epsom salt in there and let the battery work good, for one more week only.
 
battery desulfation using PWM spikes can hit 40V+. the spike is very shortlived and is [hopefully] absorbed in filter circuits in the car's components before they can do any harm.

It takes MONTHS on one of these devices to show any differences.

as I believe I posted earlier--- I have made these and measured their performance some years ago. They are not a panacea and don't work in all circumstances. And, one destroyed a battery charger, over time when used for several months. And in another instance, the jeep's computer got a little wonky after a weekend on the desulfator. mine spiked at *up to* 60V.

Batteryminder's 20V is enough for marketing to call it such, but won't really be effective unless it's truly on battery for months.
 
I have one of those smart chargers that do desulfation. My lawn tractor came with a DieHard battery (not gold) that lasted 3 years. I replaced it with a DieHard Gold and desulfate it every fall prior to storage for 2 cycles (48 hrs). I also charge it every 1.5 to ensure it's fully charged. The battery is now going on year 7.
 
Yes battery desulfators work! Those that tell you otherwise have either not tried one, tried one on a damaged battery, or are a battery salesman. We use these devices regularly and have revived many batteries we were told were no good. We even keep a blog journal of customers testimonials sharing there stories of success (and failure).

In regards to the BLS unit you speak of, from an insider that sells these, I would share that these units have our highest return rate for on-board desulfators. The PulseTech PowerPulse has a zero percent return rate and the VDC BatteryMinder a tiny handful come back. This may be due to the promotion Battery Life Saver had where you could return the unit after 3 months of use...we think people were fixing there battery issues and then returning for a full refund; essentially "renting" the product.
 
Originally Posted By: wrcsixeight
Better off just pouring some epsom salt in there and let the battery work good, for one more week only.

Yikes! Don't do that! This will change the chemical makeup of the battery and create issues further down the road. You would be better off flushing with distilled water to remove sediment. Better yet using a product like Battery Equalizer.
 
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