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TECHNICAL DESCRIPTION OF THE SULPHATION PROBLEM
AND THE MEGAPULSE SOLUTION
- Index:
- Megapulse specification
- All about batteries
- How a lead-acid battery works
- How Megapulse works
- Measuring a battery's performance
- Issues with small sealed/flooded lead acid batteries
- The effects of sulphation
- The benefits of removing sulphation
- How sulphation destroys a battery
- The ways sulphation kills a battery
- Primary causes of sulphation
- The effects of hot and cold climates
- What can be done to remove sulphation
- The two battery killers: sulphation and electrolyte stratification
- Pictures of a sulphated battery, and the action of Megapulse
- Animation describing battery revival with Megapulse
- Comparison of Megapulse to other desulphation methods
- Why a sulphated battery causes alternators, starter motors & electrical components to fail
- The problems with silver calcium batteries
- How Megapulse safely keeps lead-acid batteries at peak performance
- Applying an equalization charge
- Table of key voltages for lead-acid batteries
- Table of SOC (state of charge) vs voltage for lead-acid batteries
- Some applications for Megapulse battery technology
How a lead-acid battery works
- A lead-acid battery uses a chemical reaction to produce an electric current. This reaction is mostly reversed when the battery is recharged. If the reaction was completely reversed by recharging, the battery life would be considerably extended. However this is not the case in normal use.
In its charged condition, the positive plates are made of lead dioxide (PbO2), and the negative plates are made of lead (Pb). Both plates are surrounded by sulphuric acid (H2SO4).
As a battery discharges during use, the positive and negative battery plates are both converted to lead sulphate (PbSO4), and the sulphuric acid is converted into water (H2O) (i.e. the acid becomes diluted). This lead sulphate, when present in a specific crystalline form, is what causes the battery condition known as sulphation.
During recharging, the reverse occurs. The lead sulphate is broken down into lead dioxide on the positive plate and lead on the negative plate. Sulphuric acid is produced during this process, thus increasing the strength of the acid. A hydrometer is commonly used to determine the acid strength, and by deduction, the state of charge of the battery.
The basic chemistry of a lead-acid battery: Pb + PbO2 + 2H2SO4 = 2PbSO4 + 2H2O
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The effects of sulphation
- Sulphation causes battery performance to suffer in a number of ways:
- Loss of Ah - battery runs down quickly during use
- Reduced maximum current - lack of power
- Increased self-discharge rate - battery runs flat by itself over a few days
- Battery boiling - battery gets very hot while in use or being discharged
- Case warping - plates expand internally causing the case to bulge or sometimes crack
- Shorted cells - the end result of plate expansion
- Sludge build-up - occurs more rapidly due to sulphation
- Shorter life - battery is replaced prematurely, having failed due to sulphation
Controlling sulphation with Megapulse eliminates or minimizes the above problems leading to a long, useful battery life, described next
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The benefits of removing sulphationsulphation
- Sulphation-free batteries benefit in the following ways:
- Negligible loss of Ah - battery maintains maximum capacity for its entire working life
- Negligible loss of maximum current - peak power maintained for its entire working life
- Low self-discharge rate - battery does not run down quickly by itself
- No battery boiling - no boiling or spatter when charged correctly
- No case warping - no sulphation to expand or warp the plates, or the case
- No shorted cells - the #1 reason for shorting cells is eliminated
- Minimum sludge build-up - minimal loss of Ah due to sludge
- Longer life - battery lasts until natural end of life (normally due to plate corrosion
All the problems caused by sulphation disappear through the use of Megapulse. Next: how sulphation destroys a battery
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How sulphation destroys a battery
- Sulphation is the name given to large crystals of lead sulphate that grow on the plates of a battery. The presence of sulphation crystals can lead to the following problems:
- They create an insulating layer around the plates. This increases the internal resistance of the battery, reducing the maximum available current. The resistance also generates heat as the battery is used, which may lead to loss of electrolyte through boiling, and/or warp the plates resulting in shorted cells.
- They reduce the amount of active material on the plates. This reduces the capacity of the battery, which therefore runs flat more quickly.
- The larger crystals cause swelling of the plates which in turn exerts pressure on the separators between the plates. As the plates press closer to each other, the self-discharge of the cell tends to increase. In other words the battery soon runs flat just by standing idle.
- Sometime the large crystals actually penetrate the plate separators resulting in a short circuit. One dead cell renders the battery useless.
While sulphation itself is reversible by using Megapulse, sometimes the effects of sulphation - such as a high self-discharge rate - may not be reversible. Using Megapulse to prevent sulphation in new batteries avoids all the above problems. Next: graphic showing the ways sulphation kills a battery
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Primary causes of sulphation
- Sulphation occurs all the time, but more rapidly under the following circumstances:
- Battery sits too long between charges. This problem is worse in hot weather (where the level of sulphation can significantly increase in a single day). In cool weather it takes a week without charge to increase the sulphation.
- Storing a battery for long periods without being trickle-charged (float charge).
- Not fully recharging a battery, so that it always remains in a partially discharged state.
- Running a vehicle battery down without recharging (deep cycling). An example of this would be using the headlights for half an hour without running the engine.
- Deep discharging a battery, not immediately recharging. An example of this would be using a golf cart, but not putting it back on charge until a day or two later.
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Hot and cold climates
- Hot climates:
- Sulphation develops in batteries far more quickly in hot climates. While a warm battery performs better than a cold one, the high rate of sulphation affects batteries very significantly. Therefore eliminating sulphation with Megapulse is important to prevent the rapid deterioration of battery performance and life.
- Cold climates:
- Sulphation develops in batteries more slowly in cold climates. Battery performance is adversely affected by cold temperatures, reducing Ah and instantaneous power available. As a result there is little margin for deterioration. By eliminating sulphation, battery performance is maintained even on the coldest of days.
- Megapulse will maximize available capacity by keeping the plates free of sulphation, thus battery voltage and electrolyte SG are kept at maximum values.
- The higher the SG value, the less likely is the electrolyte to freeze, which is a serious consideration at sub-zero temperatures.
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What can be done to remove the sulphation
- Megapulse is an electronic device that prevents and reverses sulphation in lead-acid batteries.
Using technology originally pioneered by the US Department of Defense, it breaks down the sulphation crystalline structure, allowing it to be converted back into lead and lead dioxide through the normal battery charging process.
This is achieved by generating shaped pulses of a specific voltage and frequency which are applied directly to the battery terminals.
Being an electrical device, Megapulse effectively treats all types of lead-acid battery, including AGM, gel and the sealed batteries.
As well as its military pedigree, its efficacy has been tested by various independent authorities around the world.
- Test reports from CSIRO, IEMW, Technische Universität, Vienna and Unitech Energy can be downloaded in .PDF format.
The unit draws between 15 and 25mA, which equates to 0.4 to 0.6Ah per day. This must be taken into account where batteries are not subject to constant or regular cycles of recharging. Setting HI or LO mode sets the voltage threshold below which Megapulse switches off. This prevents the battery being completely discharged during long periods of inactivity.
- How to install and use the Megapulse battery conditioner
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How Megapulse works
- Megapulse's performance and diagnostics are controlled by a microprocessor. As a result, battery (battery bank) life and performance is maximized, while the diagnostics provide a real indication of the battery's state.
- Operation:
- Megapulse continuously outputs shaped pulses of a specific frequency that resonates with the sulphation crystals
- The pulses prevent sulphation forming, and eliminate any sulphation that may be present
- Megapulse uses the power of the battery being treated, so no external power is required
- The microprocessor monitors the battery's internal resistance, and adjusts the pulse output accordingly.
- By eliminating sulphation, battery performance and life is maximized.
- By using low power pulses, Megapulse never over-stresses the battery.
- Diagnostics (12v / 24v):
- Every 30 seconds, Megapulse checks the battery voltage. If under the minimum threshold, it switches off to prevent excessive discharge. When the battery voltage rises above the minimum threshold. it automatically resumes operation.
- Every 29 hours, Megapulse places a 30A load across the battery (or battery bank) for 1/200th second
(0.00004 Ah), but only if the battery voltage is less than the High/Window mode threshold (e.g. <12.8v for a 12v battery). Otherwise, no load test is performed. - The microprocessor notes the battery voltage before and after the 30A load test:
- If the battery voltage drops by < 2v, the battery condition is deemed 'good': green LED on
- If the battery voltage drops by > 2v, the battery condition is deemed 'poor': red LED on
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Why a sulphated battery causes alternators and electrical components to fail
- A badly sulphated battery will cause the following to happen:
- The battery voltage is depressed
- The battery's internal resistance is high
- Alternators will work at higher current output trying to increase the battery voltage in a bid to charge it
- Alternators will work longer at higher current output because the voltage will not rise, or rises very slowly
- Heat will be generated in the battery as a result of high internal resistance and higher alternator charging current
- Battery electrolyte will boil off as a result of the heat during charging
- Battery plate warping will eventually occur as a result of the heat during charging, destroying the battery
- Vehicles will struggle to function on reduced voltages, especially ignition systems, lights, electronic components such as computers and two-way radios, and tail lifts on trucks.
- Starter motors will overheat as a result of lower voltage and higher current load, therefore failing sooner
- Alternators will fail as a result of having to work longer at high current output and overheating.
The cost of allowing battery sulphation to occur is way above the cost of fitting a Megapulse unit, and that does not even include the inconvenience of dealing with the failures: the cost of loss of vehicle usage.
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Some applications for Megapulse battery technology
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- Cars, lorries, buses
- Mining and earthmoving vehicles
- Electric vehicles such as
- Ships and boats
- Light aircraft (subject to regulations)
- Caravans, motor homes
- Solar- and wind-powered systems
- Emergency lighting systems
- Borehole pumps
- UPS (uninterruptible power supplies)
- Battery-powered gate motors
- Alarm system power supplies
- High-powered torches
In other words, any application that uses lead-acid batteries!
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