Failure Modes of Lead Acid Battery described in detail. Advantages of Sodium Sulfate Lr grade Powder & Tablets. Sodium Sulfate LR Grade is a battery life saver which prevents battery by early premature failure It is used in electrolyte of free flooded conventional lead acid & VRLA batteries. By adding common ions (Sulfate Ions) to the acid electrolyte reaction, it will increase the sulfuric acid concentration and hard ions of lead Sulfate will soluble so fast, so that the specific gravity increases up to a level in all cells of lead acid batteries.How Sodium Sulfate Tablets Work In Lead Acid Batteries? Sodium Sulfate are highly water soluble salts and they dissociate in water, producing Sulfate ions. Concentration of these salts have been kept at such level that conductivity is high and this helps electrical current to pass through it. The addition of sodium Sulfate provides an inventory (excess) of Sulfate ion that are available for more conductance. the growth of larger crystals, called hard Sulfate occurs by a dissolution precipitation process when the battery is in a discharged condition. Sulfate ions are common in both charge and discharge reactions. The reaction is also known as double Sulfate theory. During discharge lead Sulfate builds up and becomes insulating material, thereby increasing internal resistance of the cell / battery. If another common conducting ion like dissociated sodium Sulfate accepts charge of the cell / battery. Whenever a solution of an ionic substance comes into contact with another ionic compound with a common ion, the solubility of the ionic substance decreases significantly. In case of Charging When Na2SO4 is added as additive in acid electrolyte, then the concentration of Sulfate ion increases, so that the solubility of PbSO4 decrease. On the other hand in case of discharging : When Na2SO4 is added as additive to in an electrolyte medium Diluted Sulphuric acid then the concentration of Sulfate ion increases, so that the solubility of PbSO4 increase. According to famous scientist, Lechatelier & his hypothesis that, when a chemical reactants are at equilibrium, the addition of more of one of the ions from another compound will shift the composition to the left, reducing the concentration of other ion and effectively reducing the solubility of the solid to maintain the equilibrium. By Adding Sodium Sulfate Sulfate into lead Sulfate, it will increases the concentration of Sulfate ions in Lead Sulfate, So that Formation of Sulfuric acid will be more faster to attend the equilibrium. By Adding Sodium Sulfate ions as electrolyte additive into lead acid batteries, the cell reaction becomes faster for the production of Lead Sulfate in case of discharging and sulfuric acid in case of charging. For More Information Whatsapp me on +91 9326816467

1. Why Battery Fails ?
Presented By
V i k a s K a p r e
(m.sc. Organic Chemistry)

2. What is meant by
Battery ?
Two or more cells connected together.
It is a storage of energy

4. What is a “CELL”
A device that transforms chemical
energy into electrical energy
It is basic building block of a
battery

7. Battery Consist of 4 Basic
Components,which is
capable of storing electrical
energy
1)Positive Plate-lead dioxide
2)Negative Plate-Spongy lead
3)Electrolyte- Sulphuric Acid
4)Separator-PVCPEAGM
Plates are made as per standard procedure for good
life and performance

11. How a lead acid Battery
works ?
 When lead dioxide of the positive
plate and spongy lead of Negative
plate reacts in presence of
sulphuric acid ; chemical reaction
takes place to produce lead sulfate
and water. useful energy from the
chemical reaction is suitable tapped
as an electrical energy

14. Battery Life (Cycle Life ) :
DISCHARGING
CHARGING
Reversible Reaction
One sequence of charge and
discharge.

16. DISCHARGING
When Battery is used to
supply current, electrons
flow from cathode (positive)
to anode (Negative) through
an external circuit resulting
in the formation of lead
sulfate at both the plates.

18. Pbo2 + Pb(s) + 2H2So4 2pbSo4 + H2o
Lead dioxide + Metallic lead + Acid Lead sulfate + Water
- +
Electric Output
Lead peroxide changing
Metallic lead changing to lead sulfate
to lead sulfate
Sulfuric acid is used up and lead sulfate is formed.
---
---
---
---
Negative
----
----
----
----
Positive Electrolyte :- The sulfate of sulfuric
(H2So4) units with active materials on
plates leaving weaker acid solution.
Hydrogen of acid and oxygen of lead
peroxide combine to form water
diluting solution.

19. CHARGING
In this process electrons from an
external source enter the
system at cathode (Negative)
and leave it at anode (Positive)
resulting in lead dioxide at
anode (Positive) and spongy
lead at cathode (Negative)

22. 2 PbSo4 + 2H2O Pbo2 + Pb(s) + 2H2So4
Lead sulfate + Water +ve plate - Ve plate Electrolyte
- +
- +
Electrolyte :- Dilute electrolyte made stronger by return of
sulfate from plates.
Negative||||||
|
Positive|||||||
NEGATIVE PLATE
Lead sulfate
changes to Metallic
(Sponge) lead and
sulfate returns
back to electrolyte
Positive Plate
Lead sulfate
changes to
lead peroxide
and sulfate
returns back
to electrolyte

23. After clearing the basic points
let us focus on the major
reasons of Why Battery fails ?
Many Types of models of
Automotive, Tubular,
stationary cells of lead acid
batteries failure due to
following major reasons.

24. Major Reasons
 1) Mechanical faults, Impurities in
Raw Materials.
 2)Heat
 3)Malfunctioning of electrical
systems.
 4)Vibration.
 5)Sulphation

25. Mechanical Faults
A. Cell Design Faults - Weak
Mechanical design, Improper
group Burning, Unreliable
connections.

26. B.Manual Production Error :- It is
very difficult to achieve precision
and accuracy using manual
assembly methods ie short
circuits , leaks , unreliable
connection and contamination

27. A ) Improper Sealing :- It leads into
the leakage of electrolyte and loss of
active chemicals and potential
safety problems.

28. A. Impurities in Raw materials :-
If impurities observed in
Raw Materials battery
performance reduces with time
due to unwanted chemical
reactions and physical changes
to the active chemicals it leads
into battery failure

29. HEAT and Malfunctioning
of electrical systems
 High cell temperature is main killer and this can be
brought about in
 following situations
 v Bad Applications Design.
 v Unsuitable cell for the applications.
 v Overcharging.
 v High storage temperatures
 v Physical damage of separators.

 Most of these conditions result in overheating of the cell
which
 leads into battery failure.

30.  Uncontrolled operating conditions
Heat is the number one cause of battery failure,
extreme heat causes the water in the battery's
electrolyte to evaporate ; further heat causes a
positive plate grids to corrode more rapidly and
shredding of active materials.
Corrosion :- Consumes of active chemicals in the
cell leading to increased impedance and
capacity loss.

31. Overcharging
Overcharging occurs when the total capacity
removed has been replaced by recharging and
the battery remaining on charge, This
overcomes overcharging creates excessive heat
that can cause the battery plates within the
cells to buckle and shed their active material.
The battery will react to the overcharge by
producing an excessive amount of hydrogen and
oxygen These gases are the results evaporates
of water molecules within the electrolyte. The
water molecules displaced by overcharging will
be replaced in lead acid serviceable batteries
but in the maintenance free battery permanent
loss will result.

33. VIBRATIONS
We knows Indian road conditions rough driving
generates vibrations and rattling of battery. It leads
premature die of battery.
In U.S. countries they put Ant vibrations pad in
each and every vehicles ; It should be protect battery
against vibration. The positive effect of Antivibration
pad is it eliminates any possible mechanical battery
failure due to rough driving conditions.

34. SULPHATION
A lead acid battery is a series of cells Both
plates are immersed into an electrolytic
solution of dil H2So4. As a battery
discharges completing the circuit,
electrons are released from both the
electrodes and both positive and Negative
are largely converted to pbSo4(s). when
battery is fully discharged.

35. According to studies by battery
council international 60% to 70%
of lead acid batteries are replaced
prematurely due to sulphation that
occurs on lead plates.

36. when a battery discharged,reaction creates energy in the
form of electric current.forming a solid residue(lead
sulphate) finally loss of sulphuric acid reduces
electrolytes specific gravity which transforms into
water.during a discharge period,the sulphuric acid in
liquid state becomes solid and the electrolytes sp.gr.
Reading drops. However charging procedure will
transform the solid crystal residue into liquid again but
doesn’t allow the lead sulphate to return totally into
liquid.(100%).some will remain fixed on the plates or
fall down to the bottom of the battery.sulphation
reduces electrolytes concentration and as a
consequences,the cell voltage is also reduced.as
sulphation increases internal resistance increases and
heat generation leads in rise of temp.

37. SYMPTOMS OF SULPHATED BATTERIES
A general lack of capacity.back up downfall
An increase in battery temp.while charging and
discharging mechanisms
A strong odour of hydrogen gas while charging
and discharging
An excessive use of water,turning the battery
weak and dried up.
A rapid rise in battery voltage while charging.

38. It is the lead ions formed in
discharge cycle which
causes problem. they
agglomerate and fuse
together with surface ions in
Sulphuric acid to form a
highly insoluble lead
sulphate in electrolyte.

39. To prevent mechanism of loss of capacity of
battery. It had been studied by analyzing
causes of capacity loss in battery by the
formation of lead sulphate layer between
the active material of the plates, It
deposits and hardens on the battery
plates. The rate of formation of this lead
sulfate passivating Non conducting layer
is inhibiting the performance of
generating electric current in battery
such battery stops accepting charging
and discharging process

40. Only sulphation or calcification will
stop the battery from operating.
Within India more than 60 %
batteries have stopped working
prematurely due to accumulation of
lead sulfate crystals on the plates,
while the remaining 40 % is due to
mechanical failures. Before
proceeding to next point let us see.

41. Electrolyte
The liquid medium through which electrical
charges or ions move It is a solution of water
and acid in certain proportions. I am suggesting
all Battery plate and Battery manufacturers for
maintaining Basic quality of our product, use
only Demineralised (DM) water. Tap Water /
Boering water consist of impurities like water
hardness, chlorine content, Heavy minerals,
contaminations are harmful for battery life.

44. Acid Stratification
means acid becomes out of water molecules and settles
down at bottom part. In lead acid batteries sulphuric
acid has more density at lower portion of the plate while
the upper portion are low in acid content and more dilute.
concentrated acid sinks to the bottom and dilute acid
raises to the top. This phenomenon is called acid
stratification.
Acid stratification causes the top of the plate to sulfate
and lower portion to corrode and fails prematurely.

46. The number one cause of mechanically
sound battery failures occurs when lead
sulfate crystals turn abnormally hard
and clog the plates surface, acid cannot
enter the pores and starves to death.

47. Sulphate occurs naturally in a lead-
acid battery however during the
charge phase some crystals remain,
accumulated and harden between the
plates to the point that normal
charging will not break them down.

48. Storage
Don't store the battery unnecessarily
at too high temperature.

49. Manufacturing
Implement necessary quality systems
and maintain records of all process
steps in factory

50. Planned Maintenance
Provide end user with recommended
operating and maintenance
procedure for battery

51. Thank You
I am saying that Battery business are
not business of present Tense, its
business of future make your
battery longer life