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Answer To The Question: Battery Desulfators - Do They Work?

A question was posted over on Bob The Oil Guy regarding battery desulfators and whether or not they work. There were some interesting answers, much opinion and some real life examples of people using these devices. User 3311 must be a battery sales man as his response said "No they don't work. Electrical snake oil..." I would suggest the opposite is true.

User 3311 had a simplistic, but theoretically correct statement, in that the double sulfate chemical reaction occurring in lead acid batteries has two sides to the equation. During discharge non-crystalline sulfate matter is left on the plates and during charging this material is mostly transformed back to the starting compounds of lead, lead dioxide, and sulfuric acid (see a detail explanation of this on our FAQ questions: What is Sulfation?). However, it is not a perfect world and inevitably something will go wrong. Batteries left in a discharged state too long will see the non-crystalline sulfate matter harden into a crystalline form. Normal charging will no longer be able reverse this effect. Even batteries left on a trickle or float charge can eventually show a sign of sulfation as the process is not perfect and some material will not get converted back. Sad, but true. This is why sulfation is the #1 killer of lead acid batteries and why battery desulfators are sorely needed.

Back in the day, before the invention of AGM batteries, charger manufacturers would increase the voltage of the battery to try and break down the hardened crystals. This boiling effect would slough off some of the crystals as well as part of the active material on the plates. It would all end up in the bottom of the battery to slush around and cause problems in the future. The immediate effect would be noticeable, but the lasting damage would ultimately shorten the life of the battery. This method would have little or no effect on AGM batteries due to the tight weave of the fibrous matt. Battery desulfators come attack the issue in a different way.

PulseTech to the Rescue!

A few years back Pulse Tech patented a pulse frequency that would dissolve the crystalized sulfate and return it to its original form. And with that the first Battery Desulfator was born! The military was (and is) its primary customer. Their pulse frequency is a range from 22-28 KHz. That is roughly 22,000-28,000 pulses per second. The years of testing has produced empirical data that shows the effect on lead plates and validates their use as a battery desulfator.

Images of Battery Desulfators Effect on Plate sulfation

The Technology behind Battery Desulfators

First let me dispel the differences between pulse charging and frequency charging which are often lumped together and used interchangeably. Pulse charging uses a burst of high voltage within the charge cycle as its primary tool to dislodge or shock the crystals into surrendering. Some of these pulses, though measured in micro-seconds, can reach as high as 60 volts! High frequency pulsing maintains low or traditional voltage ranges and adjusts the wave and amplitude according to the manufacturers specifications. Both techniques can be used congruently. Battery desulfators can be used on all types of lead acid batteries including AGM and Gel. [SIDE NOTE Do not use a pulsing charger on a lithium battery. These batteries have a built in battery management system (BMS) and are chemically different. A non-pulsing lead acid type charger can be used on a similar voltage lithium battery.]

There are 4 basic wave forms used. The original one is named after the patent holder and is called the PulseTech Pulse Waveform. This microprocessor controlled pulse rapidly rises in less than one microsecond to its maximum amplitude and gradually returns to zero. There is no abrupt stop, no battery drain and is controlled via a separate circuit independent of the charging circuit. Battery Minder uses a similar hybrid waveform where they combine moderately high voltage pulses with their short duty cycle.

The Sine Wave version fluctuates gradually between positive and negative charge. This pulse is much "softer" than the others and may have limited effect on the sulfate crystals. The upper voltage range must be carefully controlled to prevent overcharging and gassing.

The remaining two wave forms are the Square Wave and Negative Pulse Wave. The square wave is used by Battery Life Saver and by its design dwells longer in the maximum voltage range before abruptly returning to zero. The negative wave is the mirror image of the square wave but has the added concern that the charge is restricted during the down cycle of the pulse.

Players In The Market

Today, there are several companies offering some form of battery desulfator. They each approach the science a little differently and each claim theirs is the best. BatteryMinder is the next best known, after PulseTech and they use a sine wave pulse form. Like Pulse Tech, they have a broad range of desulfation battery chargers, solar panels and on-board units. Battery Life Saver makes on-board "battery rejuvenators" as they call them, which utilize a variant known as the square wave pulse. WizBangPlus is a smaller player in the market that uses frequency pulsing in the range of 0.8 - 1.2 KHz. We have never used or tested one of the WizBang units and do not know what type of waveform they use (i.e. sine wave, square wave, negative pulse wave, etc.).

Some people, in the forum post that prompted this article, suggested users should use a CTEK 3300 to satisfy their sulphation needs. We do not think the CTEK charger lives up to its claim and feel it should be avoided if desulfation is your goal. In fact several years ago [November 2010] when we noticed batteries did not seem to respond, we contacted Borje the president of CTEK and he agreed to purchase a XC100-P Pulse Tech charger to do a comparative analysis. After some dialogue we never heard back from Borje or CTEK and frankly got the cold shoulder. To us this suggested our results were validated and their product was indeed inferior. Otherwise we would have expected a report showing how they outshine the competition.

We Know Battery Desulfators Work!

I personally would avoid high voltage pulsers and stick to the frequency based battery desulfators. Putting up to 60V into a 12V battery, even if for only a fraction of a second, just does not sound like it will produce the best long term effect. There is merit to the combination of moderately high voltage pulses combined with a frequency pulsing that Battery Minder uses. Our testing of their products is not as extensive as with the PulseTech battery desulfators.

We have posted previously, stories of our own staff testing and using the Pulse Tech XC100-P charger. (Click here to read Chris's experience). We know first-hand battery desulfators work. As to which company has the best technology we will leave that decision up to you. Hearing your experiences with these devices and opinions that come from testing them are welcome. Please feel free to share your desulfation story and help make a believer of those who say it is nothing but snake oil.

For a full listing of the battery desulfation products offered by Impact Battery see our website

  • James N Hall

    With the weather below freezing this week, I thought about the battery desulfator I installed on my dodge truck battery years ago. Probably at least 7 years ago on Maui. I was looking at rejuvenating batteries and installed one on my truck after the garage told me that my 2 year old battery need to be replaced.
    I used my rejuvenation charger to take the battery through a discharge and charge cycle to free up sulfates from the battery plates.
    Since installing this unit, not only was I able to keep the battery the garage wanted to replace, but it spent years operating on Maui, moved to Oregon and it survived the extreme cold and heat and even a few months parked in the cold, after which it started right up.
    I have driven the truck through out the United States in all sorts of conditions.
    I ended up in Virginia 2 years ago and the battery is still going strong through harsh winters and boiling summers. I have not needed to jump it once in all those years and I am on track for maybe 10+ years on that battery. I would say desulfator should be a standard installation on any battery.

  • Brian Freeman

    I'm going to cheat a bit for the sake of speed and ask a question that may be answered elsewhere in this extensive article and comments:

    How is the desulfation process applied to batteries as an ongoing maintenance process? Specifically, can it safely be done *while* the battery is recharged (to maximize the battery life), or should it be performed *separately* from the charging process?

  • Cezary Zbikowski

    Does de desulfator has any negative effect on the inverter in solar system_?

  • Jesus Baeza

    I need some advice. I have 16 solar rolls 6v lead acid batteries on an off grid cabin and when I went 1 week later to the property, when I went into my solar shed I found that all the batteries were empty when just the week before they were full. The outside temperature got really high during that week 100 degrees. I looked online and these batteries range from 400-2000 dollars each so if desulfation will work for me that would be great but I have zero experience in working on batteries if anyone can help that would be awesome.

  • Why Battery Companies Do Not Like Desulfators

    […] have saved users hundreds of dollars in replacement costs. It is worth spending the time reading blogs and other articles to keep up on what works and what is marketing hype. Every now and then I come […]

  • danhammack

    A desulfating charger will damage a lithium battery.

  • danhammack

    I bought the PulseTech Xtreme for my Honda ST1300, the 2 station model, and neither station worked correctly on my motorcycle, even though the battery had been connected to a Battery Tender previously, so there was no problem with the battery. Also when I would hook the PulseTech up to my car it worked fine. PulseTech tried to convince me that there was a problem with it, but I wasn't sure I believed that since it worked on my car. I also wasn't about to start absorbing shipping costs to try another, only to possibly find it didn't work either, and have to return again at my cost, so I returned it for a refund.

  • Hussam Rayya

    hi, in Syria there is very wide use of lead acid batteries , we use car batteries 12 v , 100 amp ) to light LED or to watch tv or to turn on routers etc .. so we extremely charge and discharge it every day for tow time at least .. thus the battery lost its efficiency after 6 months or so ... do u think some kind of desulfators can help to re-back at least 50% of its efficiency? this would save a lot of money for millions of people .. what is the solution by your opinion ?

  • Marduk

    The pulse system does not work. Period. It actually is , and potentially damaging method of charging batteries.

  • Jeff Johnson

    So you guys think Leno and several supercar makers shouldn't be putting their money on ctek devices? Disparaging other products without evidence isn't a trait I look for in a manufacturer.

  • impactbatt

    Warning SPAM!!!!

  • The Oatmeal Savage

    Listening to the snake oil BS presentation isn't quick.
    Forrest Gump was more succinct when he rambled on about shrimp.

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    Good article! Pulse Tech may be pricey, but their passive battery desulfator may be worth a try.

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  • Mikado Cat

    I've been looking at desulfators for a couple decades, and I have yet to see even a basic independent test verifying they work. It doesn't feel much like science, it feels like marketing. By independent, something like a scholarly paper, anything other than vendors and fanboys.

  • Benjamin Bargman

    This has been very helpful in narrowing down my choices, but I have one concern that was not addressed in this post, and is holding me back from making a final decision.

    From what I have read I like the charging method of the PulseTech desulfators/chargers the most, but they don't have a temp sensor for temp compensation like the BatteryMINDERs do. Is this something that I should be worried about in my decision or is it more of a marketing gimmick?

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  • Elizabeth Leila L'Abate

    A friend designed a de-sulfator that works by using a high-pitched sound to dissolve the sulfer, rather than pulsed current, which seems to be different technology...he's getting orders from all over the world, but has also made the plans for how to make the device FREE on Creative Commons....I don't know how his device compares in effectiveness to these devices, but his seems to work on almost any type of battery, with potentially better results tha from what I see here...

  • Patrick

    Hi, just bought the PusleTech Xtreme charger from you guys. After just one weekend of being desulfated, my motorcycle battery is already showing significant signs of recovery. I'd like to ask how fast/slow these desulfators work. If I were to assume my battery was just this side of dead from sulfation (resting voltage was 11.5-12.0), how much total desulfation time do you think it'd take to get it back to "almost new" condition (or as close to it as a battery its age can get)?

  • Arthur Gooding

    I have used the Battery Minder Plus (1 amp) pulse charger for years. I used to get 2 years out of a lawn tractor battery, now I leave it plugged in while not using the tractor and am still using the same battery after more than 6 years. I now have 7 Battery Minders and use them on all my small machines that sit for long periods without use.

  • Josh

    Hi, I have a 260ah AGM Deep cycle battery. Is there any harm i can do by connecting my 'WizbangPlus' battery desulfator all day everyday (24/7). If it is on the battery when my 25amp Projecta intelligent charger is also on will this damage it? Can you guys test a Wizbang charger?? Thanks alot

  • Steve

    Hi I am interested in purchasing a battery charger with this technology or just the desulfator I have several batteries that need some TLC I have emptied one of the batteries washed it out with deionised water and got lots of crud out then refilled with sulphuric acid and recharged but it doesn't seem to hold above 11.5 volts and similar probs with the others they are high amp output over 650 amps but can't find anything in France or Europe. Can you suggest a website or retailer that sells over here?
    Many thanks