Lead acid battery manufacturing process

ABSTRACT
This article gives an over view of lead acid battery
manufacturing process, material and equipment. This
will provide basic information for the students and
professional wish to start their carrier in Battery
Industry.
Written By
Imran Shahnawaz
M.Sc. Analytical Chemistry
EMBA General Management

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History of Lead acid Battery
The French scientist Nicolas Gautherot observed in 1801 that wires that had been used for
electrolysis experiments would themselves provide a small amount of "secondary" current after
the main battery had been disconnected. In 1859, Gaston Planté's lead–acid battery was the first
battery that could be recharged by passing a reverse current through it. Planté's first model
consisted of two lead sheets separated by rubber strips and rolled into a spiral. His batteries were
first used to power the lights in train carriages while stopped at a station. In 1881, Camille
Alphonse Faure invented an improved version that consisted of a lead grid lattice, into which a
lead oxide paste was pressed, forming a plate. This design was easier to mass-produce. An early
manufacturer (from 1886) of lead–acid batteries was Henri Tudor.
Using a gel electrolyte instead of a liquid allows the battery to be used in different positions
without leakage. Gel electrolyte batteries for any position date from the 1930s, and even in the
late 1920s portable suitcase radio sets allowed the cell vertical or horizontal (but not inverted) due
to valve design (see third Edition of Wireless Constructor's Encyclopaedia by Frederick James
Camm). In the 1970s, the valve-regulated lead–acid battery (often called "sealed") was developed,
including modern absorbed glass mat types, allowing operation in any position.

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Preamble
A battery is a combination of two or more electrochemical cells which store chemical energy which can be
converted into electrical energy. A battery has two poles or posts. The positive battery post is marked ‘ + ’
and is larger than the
negative post which is usually marked ‘–‘. The polarity of the charger and the battery must always match to
avoid damage to the battery and charger.
Each battery consists of six electrochemical cells and each cell possesses 2 volts potential difference. The
overall voltage of battery is 12 volts and the capacity of battery is rated in Ampere hours.
Ampere-hours
(A.h) is the product of the time that a battery can deliver a certain amount of current (in hours) times that
current (in amps), for a particular discharge period. This is one indication of the amount of total energy a
battery is able
to store and deliver at its rated voltage.
The production process
followed by Atlas Battery Limited and Exide Pakistan Ltd. for the manufacturing of Lead Acid Dry Charged
Battery comprises of following shops.
 Alloy shop
 Separator Shop
 Grid casting shop
 Paste Mixing
 Pasting Shop
 Pasted grid curing
 Formation Shop
 Cutting Area
 Assembly Line

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The complete process of battery manufacturing may be explained by the help of flow chart as shown here.

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Introduction
Lead-acid batteries, invented in 1859 by French physicist Gaston Planté, are the oldest type of rechargeable
battery. Despite having the second lowest energy-to-weight ratio (next to the nickel-iron battery) and a
correspondingly low energy-to-volume ratio, their ability to supply high surge currents means that the cells
maintain a relatively large power-to-weight ratio. These features, along with their low cost, make them
attractive for daily use.
The batteries cells are not made with pure lead but have small amount of Antimony (Sb), Tin, and Arsenic
alloyed in the plate material to strengthen the plates and make them easier to manufacture.
An Alloy is a mixture containing two or more metallic elements or metallic and nonmetallic elements
usually fused together or dissolved into each other in molten state.
Alloy is combination of elements that are added in a specific ratio to enhance mechanical properties of
reclaimed lead. The Alloy composition used is given below.
Alloy Composition
The basic objective of Alloy shop is to fulfill the requirement of Alloy in the entire battery manufacturing
process. However the objectives of Alloy shop can be summarized as given below.
 To provide KL- Alloy as raw material to Grid Casting Shop, lead parts casting machines and welding stick-
casting machines.
 Keeping record and marking of incoming reclaimed lead from different suppliers.
 Supervision of Unloading Reclaimed Lead from supplier’s vehicles.
 Keeping record of Dross weight to ensure its allowed percentage in lead.
 Keeping record of wastage material from ABL departments.

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Layout of Alloy Shop
The Alloy Shop comprises of furnaces, Ingot casting conveyor machine and part casting machines. The
details of each are mentioned below.
FURNACES
Furnaces installed in Alloy Shop are of two types. Automatically Operated Gas fired Furnace and Manually
Operated Gas Fired Furnace.
Manually Operated Gas Fired Furnace
The ABL/EPL Alloy Shop contains two furnaces of this type each having capacity of 2.5 tons of molten lead.
Lead ingots are loaded into the furnace by help of forklift. The furnace is ignited manually and initially pilot
valve is opened for ignition then main valve is opened to get complete flame. Temperature of furnace is
determined from digital thermometer.
Automatically Operated Gas Fired Furnace
There are two automatic furnaces installed in the Alloy Shop. The capacity of the each furnace is 3.5 Ton of
molten lead. Lead ingots are loaded into the furnace by help of electrically operated crane. The furnace has
fire blower system to ignite the main burners.
The procedure to ignite the main burner of furnace is given below.
• Blower is started to remove the accumulated gases.
• Igniter ignites the pilot flame.
• Flame sensor (Photo Sensor) senses the flame and then open main gas solenoid valve.
• Thermostatic system is used to maintain the furnace temperature.
INGOT CASTING CONVEYOR MACHINE
The machine is used to cast lead ingots. The machine setup consists of a conveyor having moulds, Lead
pump and automatic furnace. The molten lead is pressurized into the lead pipe by the help of centrifugal
pump. The molten lead is poured into mould and then sprayed with water to increase rate of heat transfer.
The machine is controlled by timing controller that adjusts the timing of mould filling and pouring of molten
lead through pump main supply. The mould is usually filled in 5 to 6 seconds. The moulds are emptied due
to inclined position of mould. These ingots are then stacked and marked with a unique number.

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PART CASTING SECTION
The section is responsible for casting of battery parts including bushes, Insert M/C “U” pins, Insert I pins,
Straps, Connectors, Terminal Poles, Welding Sticks and Bus Bars. The manual die casting machines are
provided for the purpose. Different dies are available for each battery type. The raw material for these
machines is KL-Alloy, which is produced in Alloy Shop. The KL-Alloy is melted in the furnace and then
poured manually into the casting die. The solidified part is ejected afterwards.
Lead Alloys
PROCESS FLOW
The Alloy production process comprises of two major steps including the preparation of Mother Alloy and
preparation of KL-Alloy. The Antimony and Arsenic are used as additives in the alloy production process.
The sources of incoming raw material used for KL-Alloy Production are as follows.
• External Source:
Reclaimed Lead procured from local vendors and suppliers.
• Internal Sources:
Melting of Washed grids obtained from pasting shop. Melting of Rejected negative plates obtained from
process.
Method For Preparation of Mother Alloy
The procedure used for preparation of Mother Alloy. The steps followed are as given below.
• Load furnace with 2500 kg of Reclaimed Lead.
• Set temperature of furnace temperature controller 500 o
C to 550 o
C.
• Remove dross from the furnace.
• Put 50 kg Arsenic pack & hang the pack in the Molten Lead.
• Hangout the pack after 60 min from furnace.
• Mixing of the alloy is done.
• Switch off the burner and pour molten alloy into the mould.
• Moulds are emptied in the form of ingots.
• Put red line mark on ingots.

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Method for Preparation of Alloy in Manual Furnace
The procedure used for preparation of Alloy in Manual Furnace. The steps followed are as given below.
• Load furnace with 2500 kg of Reclaimed Lead and set the furnace temperature to 500-550 o
C.
• Remove dross from the molten lead in furnace.
• Check Antimony from the quality inspector and complete antimony as per given standards and procedure
of checking is described in article 3.
• Weigh and mix the required amount of Antimony.
• Add 5 ingots of Mother Alloy.
• Quality inspector checks alloy quality.
• Pour Alloy into the moulds.
• Spray water for rapid cooling of mould and to increase heat transfer rate.
• 24 ingots are stacked in one group.
Method for Preparation of KL-Alloy in Automatic Furnace
The procedure used for preparation of Alloy in Automatic Furnace. The steps followed are as given below.
• The crane is used to Load furnace with 3500 kg Reclaimed Lead and set the furnace temperature to 500 –
550 o
C.
• Remove dross from the molten lead in furnace.
• Check Antimony from the quality inspector and complete antimony as per given standards and procedure
of checking is described in article 3.
• Add 7 ingots of Mother Alloy.
• Insert Lead Pump into the furnace and flame its burners.
• After 10 minutes, Switch on the conveyor machine.
• Quality inspector checks alloy quality.
• KL-Alloy is automatically poured into the moulds by the lead pipe nozzle.
• Water is sprayed for rapid cooling of mould and to increase heat transfer rate.
• 24 ingots are stacked in one group.

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Procedure for Checking Antimony In Furnace
Quantity of antimony present and required to add is determined by the following procedure.
• Take a sample of molten lead from furnace by the help of a spoon.
• Insert thermometer probe into the molten lead and wait for its temp to lower down.
• The moment the molten lead starts to change phase then temperature become stable.
• Note down that temperature and use chart against that temperature to add suitable amount of Antimony
into the furnace. The range of temperatures for antimony addition is 304 to 322 o
C.
Lead Alloys
Alloying Plant may capable of producing all kinds of Lead Alloys i.e. Antimonial, Calcium, Selenium, Copper,
Tin, Arsenic etc. We have Alloying Kettles of various capacities ranging from 7-30 tones per batch. They are
fitted with high efficiency furnace oil burners equipped with preheating arrangements. Emissions control is
achieved by a flexible kettle hood venting into a venturi scrubber attached to an ID fan along with a
chimney/stack arrangement. Emissions are regularly monitored to ascertain that they strictly fall within the
allowable limits.

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Calcium – Lead Alloy
Elements (%) Limits
Calcium (Ca) 0.120 +/- 0.020
Aluminum (Al) 0.030 +/- 0.010
Tin (Sn) 0.400 +/- 0.100
Other Impurities
Applications : For making Automotive/Tubuler/SMF/VRLA battery plates.
Antimony- Selenium Lead Alloy – 2.5
Elements (%) Limits
Antimony (Sb) 2.500 +/- 0.250
Arsenic (As) 0.150 +/- 0.050
Tin (Sn) 0.250 +/- 0.050
Selenium (Se) 0.020 +/- 0.005
Other Impurities
Within Specified
Limits
Applications : For making Automotive / Tubuler grids.

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Antimony Lead Alloy – 3.0
Elements (%) Limits
Antimony (Sb) 3.000 +/ – 0.250
Arsenic (As) 0.125 +/ – 0.025
Tin (Sn) 0.250 +/ – 0.050
Sulphur (S) 0.003 – 0.008
Copper (Cu) 0.040 – 0.060
Other Impurities Within Specified Limits
Applications : For making small parts in HD batteries, also in COS Fusion
Antimony Lead Alloy – 4.5
Elements (%) Limits
Antimony (Sb) 4.500 +/ – 0.250
Arsenic (As) 0.150 +/ – 0.025
Tin (Sn) 0.250 +/ – 0.050
Sulphur (S) 0.003 – 0.008
Copper (Cu) 0.040 – 0.060
Applications : For making automotive / Tubuler Grids

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Copper – Lead Alloy
Elements (%) Limits
Copper (Cu) 0.070 – 0.080
Antimony (Sb) 0.001
Arsenic (As) 0.001
Tin (Sn) 0.001
Bismath (Bi) 0.030
Iron (Fe) 0.001
Zinc (Zn) 0.001
Silver (Ag) 0.005
Applications : For making Lead Pipes / Chemical reactors

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Tin – Lead Alloy
Elements (%) Limits
Antimony (Sb) 0.005
Arsenic (As) 0.001
Bismath (Bi) 0.030
Iron (Fe) 0.001
Copper (Cu) 0.005
Tin (Sn) 20 – 80 (As per requirement)
Applications : For making Solder Alloy
Objective of Grid Casting Shop
The basic objective of Grid Casting Shop is to fulfill the requirement of grids in the entire AGS battery
manufacturing process. However the objectives of Grid Casting Shop can be summarized as given below.
 To provide all type of grids as raw material to Pasting Shop, lead parts casting machines.
 Keeping record and marking of Alloy received from Alloy Shop.
 Keeping record of wastage material from Grid Casting Shop.
LAYOUT – GRID CASTING SHOP
The grid casting shop comprises two sections i.e. Grid Casting I and Grid casting II. Grid casting I consist of
two types of machines i.e. New Ganglih Machines and Old Conventional Machines. Grid Casting II consists
of only Old Conventional Machines.
The production of Grid casting shop continues for 24 hours and it is divided into three shifts of 8 hours.

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Each operator is given a target production i.e. 4200 panels for smaller grids and 4000 panels for larger
grids.
DEFECTS OF GRIDS
The grids quality parameters are dependent on three variables i.e. Grid Weight, Grid Thickness and Grid
physical condition. The following defects are observed in the grids.
a. Short Molding
b. Lead Tear
c. Grid Cracking
d. Grid Lugs deshaped
The some of the factors causing grid defects are as given below.
a. Spray Vanishes
b. Furnace , Ladle and Mold Temperatures
c. Mold Physical condition
d. Machine Physical Condition

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LEAD OXIDE POWDER MAKING PLANT
Ball Mill Process - Lead pigs, or ingots are charged with air into a ball mill. Frictional head generated by the
tumbling lead ingots initiates and oxidation reaction. Oxygen in the air, assisted by the heat of the tumbling
lead, reacts with the lead to produce lead oxide. During milling, the lead oxide that forms on the surface of
the ingots and fine particles of un-oxidized lead are broken off, forming a fine dust that is removed from the
mill by a circulating air stream. Centrifugal mills and cyclones are used to collect large particles, while the
finer particles are collected in a bag house.
a) Rotating (drum): It is closed cylindrical drum, made of steel. The process of colliding lumps/cylinders with
itself and wall of drum, and reaction with oxygen occurs inside this closed drum.
b) Transmission group: The rotation of the drum is done by means of a reduction gear group, which
transmits the motion to the pinion and crown, which is connected to the rotating drum. Transmission
system is driven by main motor through multi-belt and pulley.
c) Lubricating system: The centralized lubricating system, which supports all moving parts, the main motor
and transmission system .The pinion and crown lubricating system is done automatically by means of a
specific pump, which greases the kinematics motion following the time set in the PLC of the machine.
d) Cooling system: The Mill inside temperature is adjusted by means of an outside water circulation and by
airflow, sucked by a fan positioned on the hood. The temperature adjusting is assured by thermocouple
that gives the temperature value and by means of the PLC, which starts the cooling system if necessary.
e) Protection hood: In stainless steel assures a suitable protection to the moving parts and enables to
collect the cooling water sprayed on the outside part.
f) Weight and Temperature controlling system: Three temperature probes fixed at three different locations
inside the body of drum. Mill has a weighing device under the main mill, which indicates the weight of
powder /oxide inside the mill .The feeding lead lumps amount depends on this weight.
Pulsaire Collectors/Filters
Lead oxide is harvested through a classifier high efficiency cyclone, bag-house filtration unit or Pulsaire
collector and induction draft fan arrangement. Fine particles of powder enter into Pulsaire Collector /filter
unit. These particles are then filtered through the vacuum cylinders/filter bags leaving its fine particles
deposited on their outer surface. Meanwhile, the high-pressure air pulses effectively dislodge the deposit
of these fine particles from the filter bag's surface and cause it to fall to the collecting hopper. The
collecting hopper is connected with conveying system, which transfers oxide powder to oxide storage silos.
Conveying System & Oxide Storage Silos
The lead oxide powder is transfer to oxide storage silos by using multi-type conveying system, which is
combination of snake conveyor, screw type conveyor and bucket elevator. The system is designed for
smooth transfer of powder without leakage of dust in surrounding or working environment.

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Snake Chain Conveyor conveys oxide through carrying blades attached to two strand special chains in an
enclosed casing. Oxide conveyed between carrying blades, which make independent chambers without
being stirred up.
There are three oxide storage silos of capacity 40 ton each. The digital weighing meter/indicator on silos
shows the quantity of oxide present in silo.
LEAD OXIDE MAKING PROCESS
Lead oxide is (PbO/PbO2) is used in lead acid storage batteries as active mass. There are three lead oxide
plants in ABL. The total production capacity oxide is about 25 ton daily/24hrs. The lead oxide making plant
comprises of four main units
· Lumps making and storage silos
· Oxide mill
· Pulsaire collector/filter unit
· Conveying system and storage silos
Lumps casting/making:
Imported refined lead 99.97% is first melted down in furnace at about 320o
C. Then molten lead is sent
through a pre-heated tube into the cylinder crown cavities by a centrifugal pump.
The lead quantity is adjustable by opening/closing the lead plug cock/adjusting screw or adjusting the
machine rotation speed. The cam near the cylinders unloading pushes up the extractors and ejects the lead
cylinders /lumps into a chute leading to buckets elevator, which feeds the cylinders /lumps storage silo. The
cooling system solidifies the melting lead before the ejection enabling the transport by means of bucket
elevator, to the cylinder silos.
Lead Oxide Mill Process
Lumps from storage silo, automatically fed into oxide mill. In the ball mill, Lead is converted to Lead Oxide,
by grinding and oxidation process, which is an exothermic process. In this process, heat is generated and
temperature of oxide is increased, to control the temperature with in the operating range of 115 to 135o
C,
the ball mill temperature is controlled with constant flow of air and with the water spraying system
controlled through solenoid valve. The fine particles of lead oxide remaining in the air stream are drawn out
of the Ball Mill and conveyed into the Pulsaire Collector.

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Pulsaire Collectors/Filters (Operation and purpose):
The purpose of Pulsaire/filter unit comprises of following two factors.
1. The first one is to keep under vacuum all the system (mill) and not to have any dust emission on the
working environment
2. The second one is to extract the lead oxide powder from the rotating chamber (where grinding and
oxidation of the metal are done simultaneously) and bring it to the hopper of the cyclone filter from where
it is mechanically sent to the oxide silos by conveyors.
The desired particle size and free Lead content ensured through proper operating parameters of plant.
Particle size checked by a test called as Apparent Density test (AD). Standard value for AD is 13~16
gm/cubic inch. Apparent density is inversely proportional to particle size.
Amount free lead and lead oxide is checked by Oxide Density (OD) test. Standard value for OD is 72~78%
oxide or 22 ~28% free lead.

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PASTE MIXER
Paste Mixer Machine description
During the paste mixing process, lead oxide, water, acid, and other chemicals are blended in a mixer to
form a thick paste. It is most important process in battery manufacturing and highly affects the quality and
life of battery. The paste-mixing machine is fully automatic and PLC controlled. The machine comprises of
following main parts.

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Paste Formula:
Ingredients POSITIVE + NEGATIVE -
Grey Oxide 1000 kgs 1000 kgs
Fibre 640 gm 640 gm
Barium Sulphate *** 8 kgs
LSA *** ***
Vanisperse *** 8 kgs
Dry Mixing 3 mints 3 mints
Holland Oil 140
(+500)
*** 2.7 kgs
Wetted
Carbon Black
*** 1.5 kgs
Water in
Carbon Black
*** 30 kgs
Wetted Mixing *** 3 mints
D-I water 134 kgs 70 ±2
D-I water timing 3 mints 3 mints
Wet Mixing 1 mint 1 mint
Acid 103 kgs 90 ±5
Acid timing 15 ±1 15 ±1
Final mixing 5 mints 5 mints
Density 4.15 ±0.1 4.40 ±0.1
Penetration 20 ±2 20 ±2
Peak Temp °C 60 ±5 60 ±5
A. PASTE TANK
It is closed cylindrical steel tank. In the upper part of tank, there are inspection doors and the hose
for cooling air inlet and outlet, the pipes for the inlet of acid and water. There are two discharging
doors on sides of tank which are used to dump the final prepared paste in cone feeder
B. MIXING SYSTEM
The rotating paddles produce a complete mixing action of the various components (lead, acid,
water and additives/expanders) to obtain a uniform and easily pasting paste.
C. COOLING SYSTEM
In the mixing cycle, cooling is essential, the temperature produced by the exothermic reaction
developed due to H2SO4 and the lead oxide. The temperature is maintained to the values fixed
using two cooling systems assuring a good quality of paste .The peak temperature limit for pasting
cycle is 60 o
C while final paste or dumping paste temperature should be less than 50 o
C. High
temperature causes hardening in paste earlier than it is used. The first Air -Conditioning (AC)

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system by means of a fan blows the paste surface for cooling, the second one by means of
circulating water, at bottom and surrounding of tank to maintain the desired temperature /cooling.
PASTING MACHINES
Machine Description
Each pasting machine has capacity of pasting over 50 thousand panels per shift/day. The
mechanisms of all the machines are almost similar to each other except difference in feeding
system. The pasting machine mainly consists of grid feeding system, Hopper with its operating
mechanism, pasting belt and operating mechanism, after hopper conveying system and PLC /main
controller
Grid feeding system: Panels are placed manually on two parallel conveyor chains. The gap
between two chains is adjusted according to grid width .Two vacuum suction feeders pick panels
from lugs automatically and place on the feeding conveyor, which feeds panels directly into hopper,
through feeder roller.

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Hopper function and operating mechanism:
Hopper is main part/components of pasting machine; the paste is dropped into hopper form cone
feeder and by combine action of rotating paddles and roller, paste is applied on panels
continuously. The main parts of hopper and their functions are as below.
a. Main Pasting Roller
The main pasting roller which is made of stainless steel, dia about 150~156cm,with lining on surface is used
for proper and compact surface on pasted plate
b. Feeding roller
Feeding roller is fixed at front of hopper, feeding roller can easily control its up and down, for avoiding that
the grid is blocked and safe grid transfer into the hopper bottom even during fast operation.
c. Trowel roller
It is used to control paste weight and homogeneity. It is adjusted according to type panel’s weight and
thickness.
d. Hopper actuating system
Hopper is driven by a separate motor and reduced gear system .The rpm/cycles is controlled through
control panel. Hopper is connected to a pneumatic cylinder, which safely lifts and lowers the hopper, lifting
is required either when grids jammed inside hopper or for cleaning of machine.
e. Hopper paddles
Paddles are designed so that appropriate paste and required conditions within the hopper are achieved.
These paddles mix the paste in the hopper and also create thrust /pressure in downward direction.
Pasting belt and operating mechanism:
Pasting belt is driven by a separate motor and reducing gear transmission system. Driving motor has a
separate electronic driver for better operational adjustment. Seamless pasting belt is suggested for better
result in pasting. Additionally, belt tensioning, roller belt squeezing roller (used to remove/extract moisture
from pasting belt) and belt scraper are equipped in the machine, which are working pneumatically.

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After hopper and before FDO conveying system:
Conveying system after hopper, which consists of small rubber roller, one pair of compact or press rollers
and one pair of acid-showering roller (not used currently). The plate Conveying system is designed to
insure safe plate transfer to FDO.
a.Compacting Roller
This steel roller, with rubber and cotton wrapped, is used to get proper thickness & compactness in pasted
plates.
b.Lugs washing system
It is used to remove extra /undesirable paste from sides of plates (lugs) and gap in-between two plates,
which is left after hopper. The combine action of stream of water and pressurized air is used for this
purpose.
c.Safety control in machines
Machine has emergency stop bar, enabling operator immediately intervening the machine operation.
Machine is equipped with all necessary guards for providing safe operation.
d.Lubrication system
There is a centralized lubrication system for all moving parts, but lubricating system is not working, which
cause frequent break down of moving parts
Flash Drying Oven:
After pasting pasted panels, pass through FDO (Flash Drying Oven). The FDO is used for drying plates
/panels and to attain the desired moisture, which is an important factor for curing process. The moisture
content as per ABL/EPL standard should be 8~11%. The speed conveyor and temperature of FDO are two
main control parameters.
Link Chain Conveyor is passing through oven to take the panels through it without affecting airflow. . Speed
of the oven conveyor adjusted automatically to match to the output of the pasting machine. The
temperature of oven is controlled through temperature controller. Inspection doors are all around oven for
easy maintenance and cleaning inside the chamber.
Collection End
At exit end of FDO, there is link chain conveyor and three rollers. The speed of chain conveyor is set in such
way that results in better overlapping of panels and operator can easily collects the panels without any
damage.

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Curing Process:
Curing of positive plates. This is the most time consuming technological procedure (24-72 hours). During
curing the following processes take place: Pb oxidation; recrystallization of 3BS, 4BS and PbO; grid
corrosion; improvement of the paste/grid contact, and drying of the paste. With increase of curing
temperature the rates of the curing processes will be accelerated and curing time can be shortened. At to >
65o
C, 3BS paste transforms into 4BS paste comprising large crystals which are difficult to oxidize to PbO2
during formation. With the new technology for paste preparation from 4BS+Pb3O4 the upper temperature
limit of curing is eliminated. The processes during curing of 4BS+Pb3O4 paste at 93o
C with H2O vapour
purged through the curing chamber have been investigated. It has been established that curing of 4BS
pastes under these conditions proceeds for less than 8 hours. Batteries manufactured with such plates have
initial capacity equal to the rated one and cycle life considerably longer than that of batteries produced
from 3BS pastes.
When curing is conducted at temperatures above 80o
C, the 3BS particles are converted into 4BS ones which
contain water. It has been established that positive plates produced with 4BS pastes cured at 50o
C have the
longest cycle life and adequate capacity performance. Positive plates prepared with 3BS pastes, which are
then converted to 4BS ones during plate curing at 90o
C, have high initial capacity and power performance
but shorter cycle life. Batteries with plates produced with 4BS and then cured at 90o
C for less than 4 h have
both satisfactory power output and cycle life.
Curing of negative plates. For high tech battery manufacture the duration of curing of negative plates
should be less than 8 hours. Additive B-88 (0.5%) to the negative paste increases the rate of the curing
processes at 60o
C and shortens the technological procedure of curing to 8 hours. Expanders disintegrate at
temperatures higher than 65o
C. The new curing mode proposed results in 10% increase in total pore
volume of cured paste and 20% increase in dry paste specific surface area, and formation of a fine-grain and
more uniform structure.
Introduction to Formation Shop
The basic materials in battery production are lead alloys to make the grids and lead oxide for the active
material. The grids are used as a support for the active material and as electric conductors for the current.
Lead oxide is produced in Ball mills operating on a surface oxidation of lead. The oxide particles always
contain some residual metallic lead which is separated and carried away by an air stream then collected in
filters.
The plates for all automotive batteries and most industrial batteries are made by preparing a paste from
lead oxide with fairly strong sulfuric acid then pressing this paste into the grids. After surface drying, the

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plates are cured in moisture saturated air at slightly elevated temperature and then dried.
The paste preparation and curing are very important steps and any mistakes or faults therein cannot be
fully repaired later. Most problems arising in formation are due to compromises in these steps.
The initial formation charge of a lead-acid battery is quite a complex bundle of chemical reactions. It is
important to know in principle about the most important parameters controlling this process in order to
achieve good reproducible results with reasonable efforts.
To begin, formation positive and negative plates are inserted into diluted sulfuric acid and connected to a
bus bar. The rectifier acts like a pump removing electrons from the positive plates and pushing them into
the negative ones. The following reaction equations are simplified showing the essentials.
Positive: PbSO4 + 2H2O --> PbO2 + H2SO4 + 2e- + 2 H+
Negative: PbSO4 + 2e-+2H+ --> Pb + H2SO4

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Charging Circuits
The charging circuits consist of electrolyte tanks, charging bus bars each for positive and negatives plates,
plastic comb and electrodes. The plates obtained from pasting shop after curing are charged in the
formation shop. The plates are loaded in the batch of 3 or 4 and charged as per method described in Article
3.1. The schematic of the charging circuit are as shown above.
The AC power supply is converted into the DC supply by the rectifiers. There are two types of rectifiers used
in the ABL. These are Dynapower and Multi functional Charger/Discharger. All tanks are connected in series
so that current remains same whereas voltage is added. The amount of current supplied to charge plates is
different for various types. It depends on the plate weight, type and active mass.

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WASHING METHOD OF POSITIVE PLATES
The washing method of positive plates is described as follows.
1. Firstly, pour water on the upper side of plates in the trolley and open drain to remove extra powder.
2. Stop the drain.
3. Fill the trolley with water.
4. When it is completely filled put air pressure hose and switches it on so that water gets into motion.
5. Continue the same for 15 min.
6. Shut off air and water valve.
7. Use pH meter or pH paper to check for acidic condition of trolley.
8. After washing, if pH is correct i.e. at 4 then don’t drain the trolley and proceed to drying section.
NEGATIVE PLATES WASHING SYSTEM
The procedure used for negative plate washing is given below.
1. Trolley is filled with water & plates are placed in trolleys, and then bring trolley to washing area.
2. Firstly, pour water into the trolley through pipe.
3. When trolley filled open the drain such that plates don’t exposed to the atmosphere.
4. Set the rate of water flow accordingly so that plates don’t expose to atmosphere.
5. Continue the same for one hour.
6. Check pH after every 15 minutes.
7. In the last 15 min check pH after every 5 min.
8. When pH standard achieve stop drain.
9. pH should be 4 – 5 on the completion of the process.
POSITIVE PLATE DRYING SYSTEM
The positive plates are dried by using Tunnel Dry Oven (TDO). The method adopted for it is described as
follows.
1. Switch on the blower and chain.
2. Ignite the burners one by one.
3. According to the plate set its zone temperatures and chain gap.
4. Set the feeding speed so that there is 10 mm gap between each plate.
5. During operation keep the temperature as per standards.
6. On completion of TDO cycle, place the plates in the racks by maintaining pitch in between.
7. Note down the temperatures in check sheets.

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8. The lubrication of the machine should also be under observation.
9. Clean the machine internally weekly.
NEGATIVE PLATE DRYING SYSTEM
The negative plates are dried by Vacuum Dry Oven (VDO). The method adopted for it is given below.
1. Before loading check for vacuum pump, steam and water flow.
2. Bring washed trolley and put plates on the table.
3. Arrange three rows of 4 x 4 into the tray and put sheet over it. Again arrange 4 x 4 three rows.
4. When both sides 15 x 15 plates arrangement is complete load the trays into VDO.
5. Bending of plate should be avoided during arrangement in tray.
6. Switch on the vacuum pump and also open water valve.
7. Note down readings of vacuum and steam after each 30 minutes.
8. When required vacuum is reached switch off the vacuum pump and water.
9. Open the valve and release the vacuum at steady pace with small opening of valve.
10. Put on gloves and remove trays from VDOs. Set them on the table.
TUNNEL DRY OVEN (POSITIVE PLATE DRYING TUNNEL)
Washed, formed positive plates are dried in heated air either in moving chain tunnel ovens with ample inlet
and outlet air supply. Drying temperatures usually range from 80 o
C to 100 o
C.
The quantity of positive plates dried depends almost entirely on the size of dryer unit itself. As a control,
drying is completed when the plates contain less than 0.8 % moisture, calculated on the basis of active
material weight of the positive plates only. It is convenient to allow the spaced positive plates to dry slowly
in air in racks. These plates in rack thereby attain the final moisture of about 2-3 %. The remaining moisture
can then be quickly removed in an oven on the requirement.

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Vacuum Dry Oven - Drying of Negative Plate after charging
This machine uses both vacuum principle and steam heating tubes which are designed to reach beneath the
negative panels drying tray, the quality of the negative plates dependent on it. The supporting plate of this
machine uses Aluminum alloy which is light and good heat conducting.
The machine only required the operator to install the negative panels into Aluminum tray, the rest of the
operation procedure will be done by the machine. The quantity is between 2160 to 2880 panels.
The production operation time ranged from 3 to 4 hours which depends on the quantity of the negative
panels to match the operation time. The vacuum requirement of the VDO is fulfilled by water-ring pump. Its
basic principle is described as follows.
The main body of a water ring pump consists of a circular casing and an impeller, where the impeller is
centered a little offset from the center of the casing.
When the impeller is rotated in the casing with a due amount of sealing water added in the casing, the
sealing water, which is greater in the specific gravity, is pressed against the inner wall of the casing by the
centrifugal force, making a concentric ring. Utilizing the changing volume of the space surrounded by the
inner wall of the sealing water ring and the impeller blades as the impeller turns, the pump performs
actions of intake, compression, and delivery continuously, with the vapors coming and going through the
suction and exhaust ports provided in the side wall or inner wall of the impeller. Rotation of higher speed
can attain more efficient exhaust. In addition, the sealing water functions as the seal so that sucked vapors
will be positively exhausted.

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PLATE PARTING MACHINE (CUTTING MACHINE)
The cutting machines are used to part the panels into two plates. There are five types of cutting machines
used which are given as below.
· Batek Cutting Machine
· Zeesar Cutting Machine
· Mac Parter
· Ganglih Cutting Machine
· JSB Cutting Machine
Panels are loaded into the cutting machine by hanging them vertically by their lugs onto a two chain
conveyor. This loading conveyor is 600 mm long panels are advanced to a feeding mechanism that transfers
them individually from a vertical to a horizontal position. Panels are fed to horizontal chain conveyor. This
conveyor consists of two outside chains with confining lugs and two center chains with lugs that support
the center trailing panel edge during parting. The outside conveyor chains converge slightly as panels travel
through the machine to allow panel feeding and give positive location for parting.

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Rotary wire brushes clean the top and bottom of panel lugs. The panel lugs are supported by the flat metal
anvil while first the top surface is brushed. Panel lugs are trimmed and panels parted by knives cutter and
then driven through. After parting, the plates are discharged onto 2m conveyor. The four conveyor chains
on the collection end table convey the parted plates which are manually collected.
Plate Cutting Method
The following procedure is used for the hand plate cutting using Ganglih Machine.
1. Set the die as per plate dimensions before starting the cutting.
2. Also adjust cutter height according to plate. Switch on the blower and the machine.
3. Place a bunch of plates on the cutting bar. Use the operating buttons to control the cutting feed.
4. Use wire brush for cleaning of cutting part.
5. Place the cut plates into the bow and tag it.
Objective of Separator Shop
The basic objective of separator shop is to fulfill the requirement of separators in the AGS battery
manufacturing process. However the objectives of separator shop can be summarized as given below.
 To provide Separators to AMB Assembly lines and MCB assembly lines as per the type of battery.
 Keeping record of physical inventory of separators and keeping minimum stock of separators.
LAYOUT – SEPARATOR SHOP
The layout of shop consists of separator production setup. The production setup comprises of machines
such as Roll Loading, Sheet Cutter, Glue Tank System, Drying Oven, Glass Mat Sticking and Fixing, Press
Rollers, Strip Cutters, Strip Stacking and Strip cutting machine

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Production Process of Assembly Shop
STACKING
This activity consists of stacking positive and negative plates in a group. The stacking procedure involves
placing alternate Negative and positive plates with separators placed in between of the two. The separators
are placed so that their Glass Mat side is always towards the positive plate. This is to minimize the shedding
of positive active mass during operation. Depending on the type of battery the type and number of plates in
a cell is determined during this activity.
ALIGNING
The stacked groups are aligned in a box to facilitate the group welding procedure. The box allows aligning
six groups at a time i.e. one battery at a time. Now this aligned box is ready for group burning.
GROUP BURNING
Those groups which are aligned in a box are burned in such a way that negative plates’ lugs are burned with
a strap or a pole which becomes a negative terminal/strap and vice versa for the positive plates
GROUP ALIGNMENT
Group alignment deals with aligning the separators in a group accurately so that no short circuit should be
observed within the group when those groups are inserted in the container. A worker checks the groups
visually so that if there is any problem with the group could be removed before the insertion.

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GROUP INSERTION
Now those welded and aligned groups are inserted in the container in such a way that there should not be
any mistake in the polarity of the group. Spacers are also inserted as they are subjected to the number of
plates.
INSPECTION AND TERMINAL ALINGNMENT
Now manual inspection is done where the workers check either the terminals are aligned or not. Workers
can also do the short circuit testing of the groups manually as the checking is provided along side.
SHORT TEST
Now the battery enters in short testing station where a short testing machine checks that battery is polarity
wise correct or not. If the battery is short circuited then it is obsolete from the line.

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INTER CELL WELDING
After short circuit and polarity test now the groups of the battery are welded together. The welding is
basically spot welding. After welding the battery is again tested for short circuit.
SHEAR TESTING
The shear testing of the welded cells is done to check either the weld is strong enough or not. The activity is
performed by a worker through a shear testing device which runs on pneumatic pressure.

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HEAT SEALING
After shear testing, the battery comes to the heat sealing machine where the container and lid is
joined/sealed together by heating them up to certain temperature.
TERMINAL MAKING
After lid sealing terminal is made either manually or with automation.

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LEAK TESTING
After heat sealing the leak testing of the battery is done. A leak testing machine checks the batteries for
leakage between the cells by applying and maintaining air pressure. The machine also checks the container
outer walls for leakage. The machine also stamps the lids with coding for the batteries.
ALUMINUM FOILING
Aluminium foiling is done on the vent plug holes where the foiling is included in the design of the battery.
CODING
PACKING
The battery which is finished in all aspects is cleaned and packed in a carton with taping on it. Now these
packed batteries are placed on pallet.

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INVENTORY MANAGEMENT SYSTEM
The inventory management system is furnished by the help of ERP and the system is designed to make the
store keeping process efficient. The inventory management system comprises of procurement process and
stores stock. The store management works on FIFO concept that is first in first out. The stepwise working
procedure of the inventory management system is given below.
QUALITY ASSURANCE & CONTROL DEPARTMENT IN BATTERY INDUSTRY
Quality Control refers to the operational techniques and activities that are used to fulfill the requirements
for quality.
Quality assurance is the process of verifying or determining whether products or services meet or exceed
customer expectations. Quality assurance is a process-driven approach with specific steps to help define
and attain goals. This process considers design, development, production, and service.
The four quality assurance steps for the department stand for:
• Plan: Establish objectives and processes required to deliver the desired quality results.
• Do: Implement the process developed.
• Check: Monitor and evaluate the implemented process by testing the results against the predetermined
objectives
• Act: Apply actions necessary for improvement if the results require changes.

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To incorporate these objectives various critical check points are introduced in the production flow process.
These critical points are mentioned below.
1. Inspection of incoming raw material
2. Chemical testing of KL Alloy
3. Weight / Appearance Check for Grids
4. Lead Lumps Tests
5. Lead oxide composition checks
6. Paste Density / Temperature Checks
7. Pasted Plate/ Weight / moisture percentage
8. Cured Plate inspection
9. Finished Plate Inspection
10. Inspection of Container, Lid, Vent Plug, Separator, Packing Material, Small Parts.
11. Electrical Tests and Inspection of Finished Product.
FINANCIAL PERFORMANCE
The battery industry in Pakistan is divided into two major segments – organized and unorganized. The
unorganized sector comprises replicators and importers of under invoiced batteries. The organized sector is
meeting about 90 % of the demand and the rest is met by the unorganized sector and imports.
The rise in raw material cost, increase in energy prices and depreciation of the Pak Rupee, pushed the cost
to higher side. Despite all these difficulties, company generated good operating results.
During the period from July 2007 to June 2008, sales of locally cars declined by 8.9 % to 164,650 units from
180,834 units during the same period last year. LCVs and pickups sales went down by the same percentage
during the same period. This was a temporary setback and the industry is bound to grow with passage of
time.
Reference:
https://batterytechnology.weebly.com/index.html
https://en.wikipedia.org/wiki/Lead–acid_battery

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