Sulfation and Its Cure
chemistry of a lead-acid battery involves plates of lead (Pb)
and lead oxide (PbO2) immersed in an electrolyte solution of sulfuric
acid (H2SO4) and water (H2O). When an external connection is made
between the lead and lead dioxide plates, electrons and ions are
exchanged between all three chemicals. The lead and lead dioxide
convert into lead sulfate (PbSO4) while the sulfuric acid converts
sulfate is formed in greater quantities the deeper a battery is
discharged. This soft, spongy material is easily converted back
into lead and lead dioxide during the battery's recharge (only
when the recharge occurs soon after discharge). If a battery is
slightly discharged for a period as short as 70 hours, the this
soft material (sulfation) will reform into a very stable covalent
bond, "locking away" active material and preventing
it from reforming into lead or lead dioxide. Each time this occurs,
a battery's capacity is reduced, eventually rendering it useless.
only does sulfation limit battery life by "locking away"
available capacity, but these formations can grow so large as
to actually cause structural damage, often resulting in an electrical
short. As sulfate crystals consume capacity, the depth of battery
discharge will become greater given a constant load. The depth
of discharge is the percentage of total battery capacity drawn
prior to recharging. The greater this percentage, the shorter
the battery life.
are 5 different energy bonding states or energy levels for the
sulfate ion. Over time, there is a transition from a less stable
ionic bond to a very stable covalent bond. In its lowest energy
or covalent bond state, sulfur forms a circular molecule consisting
of eight atoms. There molecules stack up like shingles to cover
the surface with a coating of circular molecules. There molecules
are very resistive. The effect is like painting the battery plate
with a resistive coating. The circular eight atom pattern is indicative
of a stable bonding arrangement which will resist efforts to break.
The useful life of lead-acid batteries is dictated by our ability
to break up these deposits.
attempts to convert sulfation began with equalization or "over
charging". This process was successful at removing most of
the deposits, but at a very high cost to the battery life span
due to the erosion of the positive plate grid structure. The process,
being highly exothermic, results in heat generation, plate warpage
and mechanical stress on cell components. There are numerous examples
of battery cells exploding as a result of equalization. Later
a safer electronic charging process known as PWM or pulse width
modulation was developed. This improved technique is still unable
to remove the oldest and most stable sulfate deposits from the
break these sulfate bonds, one must raise the energy level of
the atoms to a point where the electrons in the outer valence
band are excited to the next higher band, leaving the atoms unbonded
in respect to one another. Each of the indentified energy states
has a totally unique frequency that must be swept through. This
is necessary to transfer the required unit of energy to this bond
which enables the excited molecule to move to a higher state.
This process is repeated until the bond reaches the upper most
or highest excited state. Then, and only then, can it be converted
to a free ion in the electrolyte. It is only by this series of
steps that the sulfate, in its more stable covalent bond, can
be converted back into the least stable lead sulfate molecule
that can be removed off the battery plate into the free ion state
patended IES Sweeping Pulse Technology incorporated within Desulfator
Battery Revitalizing Systems is the best solution for the elimination
of lead sulfate deposits with no harmful effects to the battery.
The charging frequency from these units will shift from 10 to
100 kilohertz. This sweeping action is required to break down
all of the various bonding states, solving your sulfation problems.