Aviation Battery Plate Sulfation and Resultant Degradation Explained

BCI (Battery Council International) reports every year millions of lead-acid batteries are prematurely discarded, the utility of the affected aircraft or equipment is needlessly disrupted, and owners spend countless man hours and dollars needlessly on replacing batteries prematurely. In fact, GAO reports show premature battery replacement (used to be) a major expense item for the U.S Army excessively cutting into the defense budget needlessly.

There is no question sulfation is the leading cause of these premature disposals and battery replacements as it is THE most destructive process determining the life of all types of lead-acid batteries. Interestingly, BCI industry studies indicate as much as eight out of ten batteries are prematurely discarded as "dead" due to excessive sulfation.

This problem plagues marine, motorcycle, and collector car batteries, but aircraft batteries are especially prone to this problem due to their typical minimal capacity, longer periods of inactivity, typical high heat storage and operational environments such as near engines and battery storage in un-insulated areas of the fuselage and wings typically subject to the hot sun. To compound these factors, many aircraft owners never tend to properly maintain their batteries with frequent supplemental charging, except when it is probably too late. However, reduced life expectancy is only part of the symptom of Sulfation.

When it comes to aircraft, the prime symptom is a battery which quickly develops greatly reduced storage capacity as the ship's only source of stored power once the alternator/regulator system fails in-flight. This means, that although a battery may still start the aircraft under normal or optimum conditions, when the alternator fails instead of having an hour or significantly longer emergency electrical power on-board, you may only have a few minutes or so! When this happens at night, IFR, or in poor weather, it can very well be life threatening.

Why Don't Batteries Last 8-10+ Years...Like They Should*?
Besides dramatically reducing your GA battery's ability to store energy (receive a normal ship's charge), battery plate sulfation has shown to prematurely "kills" more batteries than any other malady.
*BCI studies say typical lead/acid batteries have enough reactive material to last 8-10+ years if properly maintained and de-sulfated.

New Battery Lead Plate
Electron microscope image of a typical lead battery plate that has never been exposed to electrolyte.
(Click Images To Make Larger)

Plate Sulfation
Typical battery lead plate of only a 6 month old battery with extensive sulfating present. (prior to de-sulfation treatment of any kind)

Over The Road Tractor Trailer Tests: A recent test on a large highway tractor fleet indicated that the highest voltage (at the battery) was 13.9 volts (no electrica1 load from the accessories). With the addition of the electrical load from the cab of the tractor (heater, lights etc,) the voltage dropped to 13.7 volts. With the addition of the trailer lights, the voltage fell to 12.3 volts. Average battery life in highway tractors appears to be approx. one year with the reason being that the batteries were maintained continuously in an undercharged state. With the addition of pulse charge/de-sulfation technology, the system voltages recovered to over 13 volts as the momentary pulsing will raise cell voltages (during the pulse) to over 15 volts. Tests indicated this momentary continuous pulse voltage in excess of 15 volts removed sulfation which "formed" on the negative plate, and allowed the battery to be maintained in optimum condition.

Normal Charging: What Actually Goes On?
During the normal discharge of a lead-acid battery, lead sulfate forms on the battery's plates. When recharged, this soft spongy material is converted back into the battery's electrolyte solution. When this material fails to release from the battery's plates, it begins to harden and crystallize. This destructive process is known as sulfation and is the prime cause of a battery loosing the capacity to be successfully re-charged. Equalizing or over-charging the battery was the only way, in the past, to remove the sulfation (PbSO4) from the battery's plates. In fact, if you talk to battery savvy mechanics they will tell you of this little known treatment largely of yesteryear... The very material that enables lead-acid batteries to release their energy and its (now) out-dated cure is what causes most batteries to fail.

After years of objective fact-finding research, Magna Labs is proud to announce the development of Pulse Technology to the General Aviation market. It has been proven that with batteries with no other problems than excessive plate sulfation, proper use of Pulse Charging Technology will enable weak and dead aircraft batteries to be "rejuvenated" and provide a longer service life and just importantly, much more storage capacity when the ships alternator/regulator systems fail.

WHAT IS PULSE CHARGING TECHNOLOGY?
Pulse Charge Technology is a patented, frequency specific*, variable boost voltage process used ostensibly to dissolve sulfate crystals back into the battery's electrolyte solution. All lead-acid batteries are adversely affected by the buildup of these deposits because as they collect on battery plates, they effectively restrict the flow of electrons and "lock away" active material required for normal operation. As this barrier becomes thicker and thicker, the battery's ability to accept a charge or deliver energy is drastically diminished, resulting in the perception that the battery is no longer usable.
*Tuned to the molecular frequency of the sulphur crystal of 3.26 MHz.

Pulse Technology allows the user to electronically dissolve sulfation formations back into the electrolyte solution without taking the battery out of service. Most importantly, if used on a regular basis, Pulse Technology will help keep the lead plates free and clean of sulfate crystals allowing it to operate unhampered at full capacity. This process generates little or no heat (to "boil" the acid away), and can in no way harm the battery itself.

BENEFITS OF PULSE TECHNOLOGY
Since the amount of exposed active plate surface is critical for determining battery output, a battery with clean plates and an unimpeded flow of electrons will accept a full charge and release all of its stored energy. Continual use of this technology will reduce battery disposal volumes, increase equipment readiness, and allow long term storage of batteries in a usable condition.

Segments of 588X enlargement of a battery's lead plate

1. Close up of new battery, just after the battery has been activated.
2. After only 6 months of misuse, (typical aircraft use cycle). Note sulfur crystals
3. After 3 months of using Aero Bat Pac Smart De-Sulfator/Charger/Maintainer

Note: Not every battery is a candidate for re-conditioning due to mechanical damage caused by vibration or contamination, which has created is "shorted" cells. If a 12 volt battery has a resting voltage of at least 10.5V and none of the 6 cells are shorted, de-sulphation of its plates can be accomplished. If you aren't able to de-sulfate any particular battery it isn't that the process doesn't work, it is most likely you have chosen a battery with a clear cut mechanical problem such as a shorted cell or plates which have already lost too much reactive material (lead) etc. Please review the instructions on how to properly evaluate a battery prior to using any pulse de-sulfator.

Every element known to man has a magnetic moment at a resonant frequency ie. a point at which the chemical bonds that hold the molecules together to form a crystal can be broken. Sulphation (the number one cause of early battery failure), is simply crystals of lead sulfate (PbSO4) which have formed on the lead storage plates in a lead-acid type battery. When a battery is improperly charged (over/under) or allowed to self-discharge as occurs during extended storage/non-use, these crystals build up on the battery’s storage plates preventing the battery from ever being fully charged and therefore able to deliver their full power / capacity. Read our "White Paper" on methods you can do to prove pulse technology works.

With their line of Aero Bat Pacs*, Magna Labs. has created a simple method of generating the required resonant frequency (3.26 megahertz pulse) to breakdown the lead sulfate crystals, allowing the molecules to return to the battery's electrolyte. By creating a wave form with the required 3.26 MHz frequency, coupled with a very fast rise time and a high amplitude pulse, more energy is developed to breakdown sulphation than by any other method believed to exist. This unique approach is now U.S. Patent Pending.
**Tuned to the molecular frequency of the sulphur crystal of 3.26 MHz.

Battery Background Information
In general, industry stats show that approx. 84% of lead acid batteries are scrapped because of sulfation which (to some extent) is a natural occurrence when the battery is discharged. Battery savvy A&P's are familiar with this problem but up to now are generally powerless to affect a cure. The deeper the battery is discharged, the more serious is the risk of excessive sulfation. Sulfation is an insulating film, which covers the plates and reduces the ability of the battery to fully accept a charge. The sulfur molecules, which form the sulfation, are now absent from the electrolyte, causing the electrolyte to become inefficient. A battery relies on clean plates and strong electrolyte to both receive charging current and offer strong discharge current. A sulfated battery can do neither. This is the prime reason an aviation battery will only tolerate a limited number of rejuvenation's or charges once they go completely "flat" from occurrences such as leaving your master switch on, etc.

An energetic recharging process will remove some, but not all of the sulfate. Eventually, after a certain number of discharge cycles, the battery plates are either coated with enough sulfate that it is impossible to achieve an efficient recharge (as in the case of motive power batteries), or the plates are eroded, and the battery is scrap (automotive batteries). Battery construction plays a pivotal role in the success rate of battery rejuvenation with pulse technology, This is the reason we recommend the use of pulse technology as a preventive maintenance tool.

Often by the time an aeromotive battery fails a load test due to sulfation, the battery plates are heavily eroded, the plate materials having fallen to the bottom of the battery. This occurs because the plates are manufactured to be of high porosity (much like a piece of Swiss cheese), to maximize surface area and to allow maximum amperage discharge for a short period of time e.g. starting your aircraft's engine). This allows construction of a compact battery with short term, high amperage capability. The sulfate enters the pores on the plates, and as it advances towards the crystalline state, it greatly expands. The crystal growth causes plate materia1 to break off much the same way as the formation of ice in a crack of a rock will cause pieces of the rock to break off.

Typical" Automatic" or "Float" Trickle Charger/Maintainers: Good, Bad, Or Ineffective?

Battery manufacturer report an un-used dormant battery and especially one in a warm or hot environment is far more more susceptible to excessive sulfation than one being used or properly recharged daily. Dormant batteries have a "discharge rate" (from about .5 to 1.5%+/- per day) depending on several factors such as amount of pre-existing sulfation, ambient temperature, and basic construction, etc. This discharge rate translates into about 50 to 80 ma per day for the typical G-35 battery. When left un-attended for long periods, the battery will sulfate rather quickly and resist further charging. While this happens it is next to impossible for a simple or even "automatic" battery charger to analyze the battery for the right amount of charge short or long-term.

This is one reason a standard, even automatic trickle charger/maintainer tends to (effectively) over-charge the battery long-term rather easily and thus "boil" out the electrolyte and ruin a battery, especially if left un-attended. Therefore, most battery manufacturers agree that leaving any type of a common charger on long-term un-attended, especially a low cost trickle chargers, can easily be harmful and isn't recommended.

IMPORTANT: Don't Mistake Our Pulse De-Sulfation/maintainer/chargers for the typical discount store "automatic" trickle chargers. Remember, if the charger or maintainer doesn't specifically say it uses "Patented Pulse De-Sulfating Technology" it isn't a computerized pulse de-sulfating device...!

Note: Pictured are samples of common (so called) "automatic" or "float" trickle chargers which ARE NOT pulse de-sulfator/chargers
Click Photo For Larger

Typical Aircraft Use: Another cause of plate erosion occurs when the batteries are in an undercharged state for long periods of time such as the typical GA, marine, RV, and collector car type installation. Again, due to sulfation once you fully discharge your battery such as when you leave your master on etc., it usually greatly limits your battery capacity to accept and hold a charge. In numerous tests including the U.S. Military (for one), pulse charge technology has shown that you can now restore batteries that have been abused and typically thought to be "junk" in the past.

Typically and not un-like marine and motorcycle, and other seldom used lead acid batteries, aviation batteries are prime candidates for excessive sulfation. Battery plate sulfation is rampant in batteries which are not used or cycled (charged/discharged) regularly and are subject to higher than ideal temperature working environments such as under the cowls and stored inside fuselage tailcones etc.

Battery theory states that the cell voltage should be up to 2.5 volts per cell i.e. 15 volts+/- in the case of a 12 volt battery) from time to time to allow the negative plate to retain proper "form". If this does not occur, the negative plate remains mushy and subject to erosion from motion and vibration etc. On 12V aeromotive systems, voltage regulator settings normally do not exceed 14.2 volts, even though BCI battery theory goes on to state that when being re-charged, a 12 volt battery must receive a minimum of 14.1 volts to maintain a healthy charged state relatively free of sulfation.

Accurate Battery Evaluation Is Key: Several models of Magna Labs pulse de-sulfators come with complete battery evaluation instructions and even a simple hydrometer to help diagnose or test your battery. While the huge bulk of premature battery failure can be traced to excessive plate sulfation, once the problem escalates to greatly reduce plate reactive material (plate shedding or fall-off), and eventually shorted cells etc, no amount of de-sulfation will help. It is vital you do some form of test to determine if your battery is simply subject to sulfation rather than suffering from other maladies PRIOR to attempting any form of de-sulfating procedure. Generally, excessive plate sulfation manifests itself as greatly reduced storage capacity and a battery which otherwise simply won't "take" or "hold a charge".

Typical Treatment Times Needed: De-Sulfation is not an over-night process. The larger the plate area and/or the more sulfation present, the longer it takes to remove same, simple. Consequently, this fact along with the fact they could better see into clear/opaque motorcycle battery cases and observe the de-sulfation process working, is why the editors of Aviation Consumer Magazine chose to do tests on the much smaller motorcycle batteries. With otherwise "junk" or greatly reduced capacity motorcycle batteries, generally the first few weeks of using pulse technology would indicate if the battery could be "saved".

Typically, with aviation G-25/35 size batteries (including sealed/gel cell, etc.) and when there are no other problems manifested such as "shorted cells" etc., you should see results on test equipment as per our White Paper tests within a 7-14" days. With batteries which have been removed from service because they will no longer hold a charge (but have no other major problems), may generally take several weeks or upwards to a month of continuous or intermittent exposure (interrupted by periods of service, etc.) for pulse technology to restore the battery. Generally, under ideal conditions when premature plate sulfation is the only problem, approx. 80%+ of the rated out-put can be restored.

With batteries which are putting out sufficient power to still be able to start the aircraft, but seem otherwise weak or test significantly below rated output on test equipment, pulse technology may increase output in as little as a few days, and go on to show dramatic differences on test equipment in a few weeks or certainly within a month. Generally, pulse technology is a way to maintain batteries long-term, not to rejuvenate them from scrap.

If in doubt as to the problems of your battery, have it professionally evaluated by a battery shop or a battery savvy A&P who has access to proper test equipment including a standard charger, hydrometer, and professional battery load tester etc.

Click Here or Call: 941-486-1960, or 877-564-6662 For Our Best "On-Line" Prices

Click Here For Basic Specs and Operating Instructions On Our "Tuned Frequency" De-Sulfators
Click Here For FAQ's On This Technology
Read our White Paper tests