Desulfator resurrects dead lead acid batteries?


Mikey Sklar, who lives off the grid with Wendy Tremayne, bought a battery desulfator kit to bring his dead electric vehicle batteries back to life. I hope it works!

I recently ordered a $37 battery desulfator kit. It looks like a pretty simple device that sends pulses to lead acid batteries to help clean the battery plates. There are many success stories on the net about resuscitating essentially "dead" lead acid batteries. Since we have two electric vehicles and live off grid we have a lot of motivation to take care of our batteries. I've seen kits that sell for hundreds of dollars, but this 555 based kit seems to kick out a lot more juice than the fancy ones with wimpy solar panels.



  1. Shitty 555 based pulse generators are like pyramids. They have been marketed for everything that ails you including a cure for cancer.

    I used to work in a small electronics store. Getting loads of people buying parts carrying some New-Age book that was going to cure their deadly disease.

    Sad really, knowing that even if these desperate non technical people got the thing to work, it still would do nothing. In a way it wouldn’t matter.

    I sincerely doubt that this will do anything positive to you battery capacity.

  2. I don’t see why one would need a kit for this, I think I can see all the parts in the picture on the website. They are like $7 at RadioShack, and you’ll end up with lots left over, as they are so cheap they won’t sell them except in quantity.

    As for whether or not it works… eh, I have a suspicion that things like this don’t work well at the very least. If you want to extend your battery life, buy a battery battery controller, one that won’t run the batteries too hard or charge them too quickly.

    I do love the 555 as a part though.

  3. One of the typical failure modes for lead-acid batteries is when the active material literally flakes off of the electrode surface. The only way to recover a battery failed in such a manner is to melt it down and re-cast it into a new battery.

  4. Seems to good to be true. Can anyone here post a link to a properly conducted (get it?) controlled and peer-reviewed trial?

  5. To do any real, significant resurrection of a nearly-dead battery, you need a big-ass commercial/industrial charger like my last employer had, a “formation charger”.

    Those will set you back a couple thousand dollars apiece. They still won’t bring back a battery that’s just plain dead, either.

    Beleive me, if there was a way for people to affordably increase the life of their batteries someone would be marketing a product for it, and even if consumers didn’t buy it, stores that sell batteries would be using them to resurrect batteries to sell them as used, since the margins on new batteries have decreased significantly with the rising price of lead.

  6. I had to design one of these for a project in my Power Electronics paper at Manukau Institute of Technology. Our focus was mostly on the design of the inductors and gate drive requirements for the MOSFET used in the design, but as part of the (breif) background study for the project I reviewed this article:

    H.A. Catherino, F.F. Feres, F. Trinidad, “Sulphation in Lead-acid Batteries”, Journal of Power Sources, Vol. 129, pp. 113-120, 2004.

    Available online at

    Australian “Silicon Chip” magazine ( published two project kits in July 2005 and May 2006.

    ‘Sulphation’ appears to be a catch-all phrase commonly used ot describe lead-acid battery failure. However there are more than 13 distinct battery failure modes, only one of which is sulphation.

    It is probably far better to maintain a battery in a healthy state by proper charging, including boost charging to equalise the cells, not over discharging the battery and not leaving it in a discharged state.

    De-sulphators may resurrect a ‘dead’ battery and may have applications for some users to maintain batteries, for example in fleets of vehicles stored inactive for long periods of time.

    At any rate, the circuits commonly used in these projects are simple and cheap enough to build. You’ll learn something about the 555 timer, inductor design and driving MOSFETs and have fun doing it :-)

  7. US$37 sounds like a lot to pay for such a kit based around a piece of buggery board.

    I costed my project at NZ$21.00 all-up.

    The basic Silicon Chip kit from 2005 with parts and etched and drilled PCB is available locally for NZ$47.90.

  8. Battery Sulfation is the end result of undercharging, deep cycling or allowing lead-acid batteries to sit completely discharged. They operate by converting lead peroxide and sponge lead to lead sulfate as they discharge. Charging reverses this process. Over time, the lead sufate converts to a more crystalline state that isn’t affected by charging (white instead of brown). Plate material also flakes off during charging. This is the combination of what kills lead-acid cells.

    They last the longest when operated under float-charge conditions and shortest when deep-cycled. About the only thing I can tell you to do to increase their life in an electric vehicle is to stop discharging when the panel indicators says they’re flat, not when the vehicle stops moving. Start charging immediately after use to bring the batteries up to float charge, never let them sit for any period of time in a discharged state (less than 2.1v per cell).

    A shorted cell just means the battery needs to be recycled, though I’ve seen (extremely dangerous, I’ve been in a shop where one’s exploded) the arc-welder method used by a farmer to bring one back for a while, but not long enough to make it worth the potential sulfuric acid bath.

    From what I’ve read on this pulse charging stuff, if it’s going to work, it will probably take a few weeks. An improperly operating pulse charger can evaporate off the water. It also can cause material to flake off the plates, potientially shorting a cell which then ruins the battery.

  9. I’m not sure that device has the capacity to restore dead batteries. I’d be shocked to learn that it works. Currently I think you’d be better off getting a new one and resist the urge to try this thing.

  10. I have end of year exams and reports due so I haven’t yet made time to properly test my de-sulphator under controlled conditions over a period of weeks as would be needed to properly de-sulphate a battery.

    However, the theory is this:

    When a lead-acid battery discarges, lead sulphate and water are produced from the porous lead oxide battery plates and sulphuric acid electrolyte. The sulphate ions can bond with the lead at three successively deeper energy levels.

    Level one bonds occur during normal charging and discharging. After a month or so at level one, some of the bonds form level two bonds wich require more energy to break.

    After more than a month at level two the sulphate ions form level three bonds with the lead and willnot conduct DC therefore no amount of recharging will break these bonds.

    These bonds occur normally and form progressively larger and more insoluble crystals of lead sulphate, soover a period of time the capacity of a battery may reduce.

    The assertion is that the crystals formed by level three bonds act as a dielectric and form a capacitive connection between the plate and electrolyte. Thus a transient pulse of sufficiently high dv/dt will pass energy through the dielectric and break apart the crystal, returning the battery from its ‘sulphated’ state.

    This process – if it works – takes weeks and many many pulses of sufficient current and voltage.

  11. Like SEB says, this only works for one of more than a dozen lead-acid battery failure modes?

    How about converting to Li-S batteries instead of trying to keep the lead in? You get greater energy density and lighter weight.

  12. I have a newer car battery charger that has some digital readouts and automatic controls. It has a mode for testing alternators and another for reconditioning batteries.
    Do you think the battery charger’s ‘reconditioner’ is basically doing the same thing, or claiming to do the same thing?

  13. Looks like SEB and GOLLUX covered it. Once you over-discharge your Lead Acid batteries, they’re toast. That’s why they make deep discharge batteries that you can deep discharge. Even then you never run them down fully.

    NiCad is much more recoverable, with full discharging and “zapping”… -don’t- use your arc welder, 3-5A is all that is needed to blow out dendrites that have penetrated the separators… and the dendrite will grow back in a few weeks. NiCad with proper maintenance has much better life than NiMh. NiMH really hate heat.

    Oh, and NiCad during charge is endothermic, they actually cool below room temp… how “cool” is that.

    Li-ion (inc li-poly, Li-Mn, Li-FePO) have removed the black art of battery maintenance… and I don’t miss it.

  14. I have used Tetra Sodium EDTA and charged the *(&#$ out of heavily sulfated flooded lead acid batteries. I don’t know about pulse kits, but EDTA works, and works pretty well. It is very important to offgas the batteries for some time afterwards.

    I live offgrid and have seen dozens of people here, as well as in the Dominican Republic, save their battery banks with EDTA. The DR has (had?) very unreliable electricity so many people have inverter / battery / charger systems for the power outages… these batteries are now treated by several retailers with “battery viagra”, which is just EDTA dissolved in purified water.

    I normally use about 2 tables spoons per cell of a golf-cart sized battery, added first to distilled water and mixed (shaking works best) until it is completely dissolved. Undissolved crystals will not dissolve in battery acid. Add the solution equally to each cell and charge until they have off-gassed and fully equalized, cycle them some and re-equalize.

    In my experience this recovers about 80% of the original capacity. It will not work to fix arced plates or cracked cases. In an extreme case Home Power (I think it was) also changed out the battery acid.

    I have a battery charger that has a “recondition” mode, seems it might help, maybe, probably a good option for sealed batteries, but I like EDTA and even know people who’ve bought “dead” batteries from a local distributor to EDTA and use in their houses.

  15. Proper de-sulphators will pulse a nice high current, enough to heat up any shorts/lead whiskers, but not enough to charge.
    555 is perfectly fine for this, though 2 are best, so you don’t need to worry about turning it off. (one turns the other on for a few hours, then shuts off totally).

    Best use for 555’s is for teaching IC design, LED brightness (ramp up or dim them) and ‘old school’ feedback cancelling.

    @ #1
    I know what you mean with the ‘Zappers’. Don’t believe it myself, but you can definately see LOTS of room for improvement on the designs.
    Well – without turning them into TENS machines if possible!

  16. Newer battery supplements such as Batteryvitamin have been shown to radically prolong the lives of lead-acid batteries by preventing certain separator growths and plate disintegration to begin with, but once a battery has already been run into the ground then unfortunately there realistically is not much that can be done to regain lost capacity and performance.

    Proper maintenance from the start is key – it’s like eating your vegetables!

  17. Wow… you guys who are dissing battery desulphation… do you believe the moon landings were faked too?

    I trust Richard Perez and the crew over at more than I trust random naysayers on the Intartubes who haven’t documented any experiments.

    People posting *actual experimentation* say EDTA and electronic desulfation will work on flooded lead-acid batteries that are sulfated, but it won’t magically restore batteries suffering from other kinds of problems. They also say PWM charging, solar panel MPPT, and self-watering battery caps all work, BTW.

    If you subscribe to Home Power magazine you will get access to their informative website. It used to be free, but unfortunately bandwidth costs have driven them to a subscriber-only model. Their technical articles are all based on real-life empirical data and real alternative power systems, with extensive photographs as well as complete system schematics and related diagrams.

    Disclaimer: I’m a long-time subscriber, I’ve got four feet of the magazine on the shelves.

    I like NimH best, they don’t explode and burn like LiIon and they are far easier to care for than NiCad, and they have a huge weight advantage over lead acid and nickel-iron cells. That being said, there are some new lithium-based and iron-based cells supposed to be coming on the market soon.


  18. This thread had me worried at first (with all the negativity), but I’m glad someone came with a journal article to clarify things.

    I like the idea of chemical solutions, too – #17 and #19. Just because the normal mode of use is electricity in/electricity out, doesn’t mean that’s necessarily the best way to fix the thing.

    Anyway, thanks all. I feel a lot more informed on the subject now. :)

  19. Don’t be fooled by the claims. “Desulfating” is another word for charging. These snake oil gadgets don’t do anything that a good, well controlled battery charger won’t do.

  20. #Three years ago I left two brand new deep cycle (very expensive) marine batteries hooked to onboard electronics, forgetting about the draw. When I went to winterize the boat, there were the batteries, at 5.5V. Junk, right?

    I bought a pulse device from a company where the engineering guy said right up front he didn’t know if it would work given the condition of the batteries. I hooked it up as instructed and watched as the weeks went by. Got discouraged, but figured what the hey, might as well let them sit. At twelve weeks, just as he predicted, those batteries attained 13.6V. A load test confirmed their capacity, and they have functioned faultlessly for the three years since. I now import the device and distribute it in US and Canada. To truck fleets, forklift users, golf cart distributors, etc. Every sale is made AFTER the customer tests one or more units for 90 days.

    I’m not going to include company or device name in this posting. That is either prohibited, or should be.

    Don’t misunderstand. I’m not saying that every such device works, nor am I saying any device works in every situation. I am only suggesting that sweeping negative generalizations are often made by people who are trying to be helpful but often have no first-hand experience.

    Thanks for taking the time to read.


    1. Howdythere, Obviously desulphator, pulse charger work as advertised. I was surprised by the cynical comments, but it’s my first encounter with this site. I can solder and suchforth, and I’ve found many sites and circuits, some apparently simpler and much more powerful than the original, but I’m about to order some batteryminder 12248 from northern tool and piss about getting them into Canada (Vancouver), so I was curious what brand you are representing.
      Best regards, Harley

    2. Ray

      Really interesting the desulphation of your marine batteries but more interesting your product.

      Can you email me details, I’m in Uk would be interested in reselling here.


  21. I’ve used the BatteryMinder for 4-5 years. Excellent. Had three batteries from the boat in parallel on the BatteryMinder all winter. All are 75%-100% capacity, checking with open circuit voltage after sitting unconnected for 24 hours. The one at 75% is 9 years old and is a crappy West Marine Seavolt flooded dual purpose.

    I used to get 4 years out of a battery in my sailboat before using the BatteryMinder. It pays back in a short time.

  22. This comment may be late. Anyway, I have few lead-acid batteries waiting to be recycled, I will try to build a desulfator and see if it works. However, I think it will all depend on how much sulphation the battery has. I also believe the best way to get the most life from your batteries is proper maintenance. Being a retired Telecom Technician, I used to work on older PABX equipment (electromechanical switches). We use older big industrial single cell lead-acid batteries with transparent casing (you can see the condition of the plates) wired in series to get a 48v output. We check the batteries weekly for proper level of electrolyte, check the specific gravity with hydrometer, check the voltage and finally we periodically equalize the charge because the system is always on float condition. The batteries lasts anywhere from 15 to 30 years, sometimes longer! Nowadays, most batteries are maintenance-free (less labor cost) but it doesn’t last as long as they used to.

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