TSP-POGC-NIGC T.T.F.

Ø
COURSE OIL AND GAS TECHNOLOGY CODE
SUBJECT BATTERY P/TM/TRG/E.BA/001

Objectives: Upon completion of this unit, the trainees should:

• Describe different the types of batteries.
• Describe the battery components.
• Describe the various modes of battery charging.
• Describe the outstanding points on battery maintenance.

Content:

1. General.
2. Different types of batteries.
3. Lead acid batteries.
4. Alkaline batteries.
5. Dry-type batteries.
6. Annex I (pictures)

Prepared by M. Alimi Checked by Y. Larijani Checked By T.T.F.

Date 10 July. 2000 Date 10 July. 2000 Date

1
TSP-POGC-NIGC × T.T.F. Ø
SUBJECT BATTERY CODE
P/TM/TRG/E.BA/001

1. GENERAL
Batteries are regarded as electrical devices used for energy storage. Batteries are charged
by a prime energy source and delivering its energy to the load on demand in following
applications:

1.1. Automotive and aircraft systems.

1.2. Emergency and standby power sources.
1.3. Emergency lighting systems.
1.4. Submarine power systems.
1.5. Power for communication equipment.
1.6. Small portable applications.

Since this training document is offered to trainees of all disciplines during the common
course period, therefore, the technical subjects and information are regarded as general.
More detailed technical data and information on batteries shall be offered during the
specific course. Subjects and paragraphs that are marked with asterisk (*) are more or less
specialized, therefore might be skipped during the common course sessions and left for
later specific course sessions.

2. DIFFERENT TYPES OF BATTERIES

Various factors and parameters that are normally taken into account in manufacturing and
selection of different types of batteries could be noted as:

- Solid/liquid electrolyte.
- Electrolyte material used in the battery.
- Battery cells material.
- High power/low power capacity.
- Long/low cycle life.
- Good/poor temperature performance.
- High/low ruggedness.
- High/low reliability.
- Long/short shelf time.
- Domestic/industrial applications.
- Sealed/unsealed battery structure.
- High/low energy density.
- High/low current rate of charging and discharging.

Depending on above specifications, various types of batteries are classified as:

2.1. Lead Acid Batteries (Introduced in This Document in Details)
2.2. Alkaline Batteries.
2.2.1. Nickel-cadmium batteries (Introduced in This Document in Details)

2
TSP-POGC-NIGC × T.T.F. Ø
SUBJECT BATTERY CODE
P/TM/TRG/E.BA/001

* 2.2.2. Zince-silver oxide batteries (introduced in this document briefly)

* 2.2.3. Cadmiun-silver oxide batteries (introduced very briefly)
* 2.2.4. Zinc-nickel oxide batteries (introduced in this document very briefly)

3. LEAD ACID BATTERIES

Lead acid batteries are the most widely used type of battery with following outstanding
characteristics:
- Low cost
- Good reliability
- Wide range of size, from one ampere-hour (1Ah) to several thousand ampere-
hours capacity.
- Capability of being manufactured in sealed and unsealed types.

3.1. Components of Lead Acid Batteries.

3.1.1. Anode
Lead dioxide (pb O2, chocolate brown) as the positive material.
3.1.2. Cathode
Highly reactive sponge lead (PbO2, grey)
3.1.3. Electrolyte
Sulfuric acid solution.
3.1.4. Chemical reaction
Following is the discharge and charge reaction of the lead-acid batteries:

Charge
Pb + PbO2 + 2H2 SO4 2Pb SO4 + 2H2O
Discharge

The state of charge of the battery can be determined by measuring the specific gravity
(relative density) of the electrolyte, which decreases on discharge and increases on the
charge.

3.2. Construction of Lead Acid Batteries.

3.2.1. Active material (lead dioxide) for each anode plate is prepared as a paste by
mixing finely divided lead dioxide and suitable expander material with sulfuric acid.
The paste is spread onto a lead-alloy grid, which provides the necessary electrical
conductivity and structure to hold the active materials. The resultant plates are
soldered to connecting straps to form positive and negative groups, which are
interleaved. Separators are placed between the electrodes and the complete
assembly is placed in a container. (Figure 1 on page 4)
3.2.2. Container material is of rigid, high-impact strength ploy propylene. (Figure 2
on page 5)

3
TSP-POGC-NIGC × T.T.F. Ø
SUBJECT BATTERY CODE
P/TM/TRG/E.BA/001

FIG.1

4
TSP-POGC-NIGC × T.T.F. Ø
SUBJECT BATTERY CODE
P/TM/TRG/E.BA/001

FIG.2

5
TSP-POGC-NIGC × T.T.F. Ø
SUBJECT BATTERY CODE
P/TM/TRG/E.BA/001

3.2.3. Sediment space is provided under the cells assembly inside the container for
safe collection of any active material that dislodges from the electrodes. (Figure 3 on
page 7)
3.2.4. Sufficient headroom is provided above the cells assembly inside the container
to hold excess electrolyte. (Figure 3 on page 7)

3.3. Electrolyte Specific Gravity (Relative Density)

3.3.1. The selection of specific gravity used for the electrolyte depends on the
service requirements and therefore should be according to the manufacturer’s
instructions.
3.3.2. Electrolyte specific gravity should be high enough for good electrical
conductivity and to fulfill electro chemical requirements and should not be so high as
to cause corrosion of the internal parts, which would shorten the life-time of the
battery and increase the self-discharge.
3.3.3. Specific gravity of 1.26 to 1.28 is usually used in automotive and high
performance batteries. For stationary standby batteries the specific gravity would be
as low as 1.21.
3.3.4. The specific gravity should be reduced in high temperature working conditions
and environment.
3.3.5. Range of decrease in specific gravity from a fully charged to a fully discharged
condition, is proportionally dependent on ampere-hour rate of discharge, and is
around 0.125 to 0.150 points.
3.3.6. A short period of time should be allowed prior to measurement of the specific
gravity after completion of the discharge to allow for equalization of the
concentration throughout the battery.
3.3.7. Trend of increase in specific gravity, during the charging period, is almost
same as in reverse trend for decrease during the discharge mode, and here again
dependent on the ampere-hour rate of charging.

3.4. Service Life of Lead Acid Batteries

Typically, higher service capacity is obtained at lower discharge rates and higher
temperatures. In general, a battery may be discharged without harm at any rate of current it
will deliver, but the discharge should not be continued beyond the point where the cell
voltage falls below a useful value. Although the lead-acid batteries are capable of operation
over a wide temperature range, but however, continuous operation at high temperatures
may reduce the service life as a result of the increase in the rate of corrosion.

3.5. Self-Discharge
3.5.1. Self-discharge in lead-acid batteries is caused by internal chemical reactions
between components of the cell plates and occurs almost entirely in the negative
electrode. Following factors influence in self-discharge of the battery:

6
TSP-POGC-NIGC × T.T.F. Ø
SUBJECT BATTERY CODE
P/TM/TRG/E.BA/001

FIG.3
7
TSP-POGC-NIGC × T.T.F. Ø
SUBJECT BATTERY CODE
P/TM/TRG/E.BA/001

- Type of lead alloy used.

- Concentration of the electrolyte.
- Age of the battery.
- Working and environment temperature.

3.5.2. The rate of discharge is normally around 15% per month at 25°C.
3.5.3. Capacity lost by self-discharge can be recovered by recharging the battery. It
is recommended that stored, standby batteries be recharged every 3 to 6 month,
since prolonged storage can cause irreversible damage and make the recharging
difficult due to sulfation of negative electrode.

3.6. Dry Charging of Lead-Acid Batteries

Lead-acid batteries, which cannot be maintained indefinitely in a charged condition after
manufacture, are usually stored dry-charged. In this condition, they can retain their charge
for as long as 2 years and put in service by adding the acid electrolyte.

3.7. Cycle Life of Lead-Acid Batteries

Number of charging and discharging practices is referred to as “cycle life” for a battery. The
nominal cycle life of a lead-acid battery is around 150 to 250 cycles.

3.7.1. For high-rate shallow discharge, the life of the battery ranges from 2 to 5
years (for automotive service)
3.7.2. Certain stationary-type batteries have been designed and manufactured for
long-term use, which offer a life expectancy from 15 to 25 years depending on their
construction.

3.8. Maintenance-Free Cells

Small sealed cells, using the lead-acid system, are now available for portable applications
in both cylindrical and rectangular-shaped cells. Maintenance-free batteries use gelled or
immobilized electrolyte, which are resistant to leakage and can be discharged in any
position. No replacement of electrolyte and water would be required in these maintenance-
free batteries.

3.9. Charging Lead Acid Battery

A lead-acid battery can be charged at any reasonable rate of current provided that it does
not lead to excessive gassing and high temperature. Two specific method of charging is
practically common for lead acid batteries.

3.9.1. Two-step, constant-current charge

In this method the charging is started at the rate corresponding to 1/5 of the rated
capacity of the battery (referred to as C/5 rate) for 5 hours or until the battery begins
to produce gas freely (around 2.4 volts per cell). The charging current is then

8
TSP-POGC-NIGC × T.T.F. Ø
SUBJECT BATTERY CODE
P/TM/TRG/E.BA/001

lowered to about 25% to 40% of the starting current to avoid hard gassing which
would otherwise take place.
3.9.2. Constant potential charging
In this method, a fixed resistor is applied in series with the charger and the battery.
Appropriate charging voltage and resistor are selected to provide the proper initial
and finishing current rate.
No further adjustment of the potential would be required during the charging.
3.9.3. Taper method of charging
This method is the modified method of constant-potential method (3.9.2.), and is a
more desirable practice, as it limits the charging current and prevents overcharge
and electrolyte loss that could occur in the constant-current method if the battery is
not removed at the completion of charging.
3.9.4. Charging of maintenance-free cells
Recommended charging rate for these type of sealed batteries is lower than that of
liquid type. The initial rate would be C/10, tapering to around C/50 for an elapsed
charging time of 20 to 25 hours.
3.9.5. Boost charging
In an emergency case, boost charging (fast charging) can be used. In this type of
charging, the current should not exceed the “C” rate, and the battery should not be
allowed to reach high temperatures, otherwise the battery would suffer damage.
3.9.6. Float charging
In this mode of charging, the charger maintains a constant voltage (around 2.2 volts
per cell), providing sufficient current to the battery to keep it fully charged, but
without considerable overvoltage. Following a discharge, the battery automatically
draws a higher current that decreases as full charge approaches, until it is again
reduced to the low maintenance value.
3.9.7. Partial float charging
Under this mode of charging, such as in automotive applications, the battery is not
continuously charged, but can receive sufficient charge only when the engine is
running at sufficiently high speed.
3.9.8. Trickle charging
Trickle charging is a continuous-constant current method applied to the batteries in
storage or standby service in order to maintain it in a fully charged condition. Trickle
current rate value is around 50 to 100 ma/100 ah of the capacity of the battery.
Since gassing occurs when the battery is fully (or excessively) charged, therefore,
safety precautions should be taken, because a considerable amount of hydrogen
and oxygen are produced which can be hazardous.

Note: Overcharging of the lead-acid batteries would lead to electrolysis of water and thus
producing hydrogen at negative electrode and oxygen at positive electrode. Therefore, due
cautions should be taken to avoid overcharging for safety reasons.

9
TSP-POGC-NIGC × T.T.F. Ø
SUBJECT BATTERY CODE
P/TM/TRG/E.BA/001

4. NICKEL- CADMIUM BATTERIES (NI-CD BATTERIES)

Nickel-cadmium batteries are widely used in energy storage and UPS systems for their
outstanding advantages and high quality performances compared with lead acid batteries.
Major specifications of Ni-Cd batteries are listed below.

- Good high power capability.

- Excellent long cycle life.
- Good low temperature performance.
- Considerably safer than lead-acid type.
- High ruggedness.
- High reliability.
- Flat voltage load servicing.
- Capable of being manufactured in many sizes, ranging from the small sealed
button and cylindrical cells (with capacities as low as 0.2 ah) to larger vented
cells for standby and emergency service (with capacities over 1000 ah).
- Manufactured in sealed type as well as liquid electrolyte batteries.

The nominal voltage of nickel-cadmium cell is 1.2V in operation, and 1.4V for open circuited
cell.

Nickel-cadmium batteries are used in following areas:

- Aircraft batteries.
- Industrial emergency power applications (UPS systems), particularly in oil/gas
complexes.
- Communication equipments.
- Photography (electronic flash units).
- Portable tools and appliances.
- Stand by powers.
- Hand-held calculators.

Nickel-cadmium batteries are designed and manufactured in two different construction

systems:
- Vented pocket plate Ni-Cd cells.
- Vented sintered plate Ni-Cd cells.

4.1. Components of Nickel-Cadmium Batteries.

4.1.1. Anode:
Nickel oxide (NiooH) as the active material.
4. 1.2. Cathode:
Cadmium (Cd) as the negative electrode material.
4.1.3. Electrolyte
Alkaline solvent, a solution of potassium hydroxide is used as electrolyte material.

10
TSP-POGC-NIGC × T.T.F. Ø
SUBJECT BATTERY CODE
P/TM/TRG/E.BA/001

4.1.4. Chemical reaction

The charge and discharge chemical reaction for the nickel-cadmium batteries is as
following:
Charge
Cd + 2NiOOH + 2H20 Cd (OH)2 + 2Ni (OH)2
Discharge
According to above chemical reaction, water is produced during the charging
process, therefore, overcharging of the nickel-cadmium batteries would lead to
electrolysis of water and thus producing hydrogen at negative electrode and oxygen
at positive electrode. For safety reasons, due cautions should be taken to avoid
overcharging of the lead-acid batteries.

4.2. Vented Pocket Plate Ni-Cd Cells

4.2.1. In this design the active materials are in powdered form (the nickel hydroxide
is mixed with graphite of flake nickel to improve conductivity) and are contained in
perforated rectangular pockets formed from thin perforated nickel-plated steel
ribbon. (Figure 4 on page 12)
4.2.2. The perforated pockets are welded onto steel frames to form electrodes of
various sizes and capacities. The perforations allow access of electrolyte, but are
small enough to retain the active material particles. The positive and negative plates
are respectively bolted together, insulated from each other and then the assembly is
placed in a plastic or nickel-plated steel container.
4.2.3. Container material is of high-impact-strength quality of plastic or nickel-plated
steel.
4.2.4. Sediment space is provided under the cells assembly inside the container for
safe collection of any active material that dislodges.
4.2.5. Sufficient headroom is provided above the cells assembly inside the container
to hold excess electrolyte.
4.2.6. The cell container is fitted with a vent, which opens to release gases
generated during charging.

4.3. Electrolyte Specific Gravity

A 20% potassium hydroxide electrolyte (specific gravity/relative density: 1.2) is usually used
in nickel-cadmium batteries. Higher concentrations give better low-temperature
performance, but at the expense of losing the operating life.

4.4. Life Cycle for Ni-Cd Batteries.

4.4.1. Nickel-cadmium batteries have better cycle life than that of lead-acid type and
range from 300 to 500 cycles.
4.4.2. Deep discharge reduces the cycle life whilst, in shallow discharge practices
considerably higher cycle life is obtained.

11
TSP-POGC-NIGC × T.T.F. Ø
SUBJECT BATTERY CODE
P/TM/TRG/E.BA/001

FIG.4

12
TSP-POGC-NIGC × T.T.F. Ø
SUBJECT BATTERY CODE
P/TM/TRG/E.BA/001

4.5. Self-Discharge
4.5.1. Self-discharge rate in nickel-cadmium batteries is substantially much lower
than that of lead acid batteries.
4.5.2. The rate of discharge in sealed Ni-Cd batteries is approximately twice that of
the vented type.

4.6. Dry Charging of Ni-Cd Batteries

Since the typical application for Ni-Cd batteries is stand by service, and that these batteries
are suitably capable of being stored fully charged and filled with electrolyte for a long period
of time, therefore the concept of dry charging is not applicable to nickel-cadmium batteries.

4.7. Charging of Liquid, Vented Ni-Cd Batteries.

4.7.1. Nickel cadmium batteries may be charged by either “constant-current” or
“constant-potential” methods, as “described earlier for lead-acid batteries (sections
2.1.9.1, 2.1.9.2 & 2.9.1.3).
4.7.2. Since the typical application for the Ni-Cd batteries is standby service, these
batteries are maintained in the fully charged condition by either “trickle” or “float”
charging. These methods of charging were described earlier for lead-acid batteries
(sections 2.1.9.6 & 2.1.9.7 & 2.1.9.8) and are applicable to nickel cadmium batteries
as well.
4.7.3. Boost charging of Ni-Cd batteries.
Boost (rapid/fast) charging of the nickel-cadmium batteries are applicable, but care
must be taken not to overcharge or overeat the battery.

4.8. Sealed, Maintenance-Free Ni-Cd Batteries.

4.8.1. Sealed Ni-Cd batteries incorporate specific design features to prevent the build-
up of pressure caused by gassing during the charge.
4.8.2. Sealed Ni-Cd batteries are available in three construction types:
- Rectangular cells.
- Cylindrical cells (Figure 5 on page 14)
- Small button cells.
4.8.3. The construction of sealed Ni-Cd batteries is almost identical to the vented
cell except for certain elements incorporated to remove oxygen gas generated
during the charge.
A safety vent is used in the cylindrical and rectangular cells to prevent rupture in
case of excessive gas build up due to a malfunction and overcharge.
4.8.4. Capacity ranges for sealed Ni-Cd batteries are as below:
- Rectangular cells: 1 to 25 Ah
- Cylindrical cells: 0.1 to 7 Ah
- Small button cells: 0.02 to 2.0 Ah

13
TSP-POGC-NIGC × T.T.F. Ø
SUBJECT BATTERY CODE
P/TM/TRG/E.BA/001

FIG.5

14
TSP-POGC-NIGC × T.T.F. Ø
SUBJECT BATTERY CODE
P/TM/TRG/E.BA/001

4.8.5. Sealed Ni-Cd batteries have many advantages as:

- Free from maintenance (no water addition or renewal of electrolyte)
- Operation in any position.
- Long storage life.
- Long cycle life.
- Good performance over a wide Temperature range. For low temperatures
and high rates, however, vented unsealed Ni-Cd batteries are preferred for their
good performance.
- Rugged construction.

4.9. Charging of Sealed Ni-Cd Batteries.

Charging of sealed nickel cadmium batteries is normally performed by the constant current
method (section 4.7)

4.9.1. Normally the C/10 rate is used and the battery is charged for 12 hours. At this
rate of charge, sealed batteries behave similarly to that of vented type.
4.9.2. Recent designs for sealed Ni-Cd batteries provide the charging rate of C/5.
But, however, due care should be taken not to overcharge the batteries and avoid
over temperatures.
4.9.3. Boost (fast) charging method is also applicable for sealed batteries, but
means must be provided to avoid overcharging and over temperature.
4.9.4. Sealed Ni-Cd batteries charging at temperatures between O and 40°C is best
recommended. Charging above 40°C in not advised. For charging below 0°C the
lower rate of charging should be selected.
4.9.5. Constant-potential charging is not recommended, as it can lead to thermal
runaway. It can be used if precautions are taken to limit the current at the end of the
charge.
4.9.6. Float charging is also possible for sealed Ni-Cd batteries, however similar
cautions, as constant-potential charging should be taken.
4.9.7. Trickle charging at a low constant-current rate normally is used to maintain
the battery in a state of full charge.
4.9.8. A periodic discharge every 6 months, followed by a discharge, is advisable to
ensure optimum performance.

4.10. Comparison Between Lead Acid and Ni-Cd Batteries.

4.10.1. Ni-Cd batteries can be stored filled with electrolyte for long periods of time
without deterioration, while, lead-acid batteries should be stored unfilled.
4.10.2. Cost of Ni-Cd batteries is higher than lead-acid batteries.
4.10.3. Ni-Cd batteries have lower losses than lead-acid batteries.
4.10.4. Freezing is not harmful to Ni-Cd batteries.

15
TSP-POGC-NIGC × T.T.F. Ø
SUBJECT BATTERY CODE
P/TM/TRG/E.BA/001

4.10.5. Ni-Cd batteries are capable of working in very low temperature. With higher
electrolyte concentration (around 30%), Ni-Cd batteries can be used in
temperatures as low as -50°C.
4.10.6. Ni-Cd batteries can be maintained in fully charged and filled with electrolyte
for a long periods of time and capable of going into service directly from the storage
without recharging. Lead-acid cannot offer such reliable quick-applicable service.
4.10.7. Normally, less maintenance practice would be required for nickel-cadmium
batteries than that of advised and required for lead-acid batteries.

* 4.11. Zinc-Silver Oxide Batteries

Zinc-silver oxide batteries, using potassium hydroxide (KOH) as electrolyte, are noted for
their high capacity per unit weights and volume (the highest of any presently available
battery), and their ability to maintain high capacity at high current drains. Since this type of
batteries are not usually used in the oil and gas industries, therefore, a general introduction
would be sufficient in this document.

4.11.1. In this type of batteries, zinc (Zn) is the negative cathode, while the silver
oxide (Ago2) is the positive anode.

4.11.2. Zinc-silver oxide batteries are available in sizes from 0.1 to 300 Ah in “low”
or “high” rate constructions.
4.11.3. Zinc-silver oxide batteries are used in following areas.
- Lightweight radio and electronics.
- Submarine equipment.
- Areas where high energy density is a prime requisite.
4.11.4. These batteries are not used for general storage-battery applications due to
their high costs.

* 4.12. Cadmium-Silver Oxide Batteries

General specifications of this type of batteries could be outlined as below:
4.12.1. Better cycle life and lower temperature capacity than the zinc-silver oxide
batteries, but inferior in these characteristics compared with the nickel-cadmium
batteries.
4.12.2. Energy density is between that of the nickel-cadmium and the zinc-silver
oxide batteries.
4.12.3. Cadmium-silver oxide batteries are very expensive.

* 4.13. Zinc-Nickel Oxide Battery

Technical characteristics of this type of batteries are almost midway between the nickel-
cadmium and zinc-silver oxide batteries. Due to lower cost, zinc-nickel oxide batteries have
considerable potential for more extensive use in the future.

16
TSP-POGC-NIGC × T.T.F. Ø
SUBJECT BATTERY CODE
P/TM/TRG/E.BA/001

5. SOLID ELECTROLYTE BATTERIES (DRY TYPE BATTERIES)

Several types of dry type batteries have been designed and manufactured using different
solid electrolytes and active materials. Solid-electrolyte batteries are designed and used
primarily for low current discharge rates (Figure 6 on page 18). The special significant
characteristics of the solid-electrolyte batteries are:

5.1. The high energy densities, 5 to 10 WH/IN3, particularly achieved with the light litium-
anode solid-electrolyte batteries.

5.2. Sealed structure, which provides protection against moisture and maintain a high-
density, void-free package.

5.3. Continuous discharge at high rates is not practical with solid-electrolyte batteries.

5.4. A significant characteristic of the solid-electrolyte batteries is their long shelf life, which
normally exceeding 15 years at 20°C.

5.5. The characteristics of several of the available types of solid-electrolyte cells are
summarized in the following table:

Energy density at 100-H rate

Cells Cells Voltage, v
WH/DM3 WH/KG
Silver anode 0.66 40 - 80 15 - 25
Lithium anode 1.9 100 - 200 35 - 70
Lithium anode 1.9 300 - 500 75 - 150
Lithium anode 2.8 250 - 500 120 - 180

5.6. Recharging of Dry Batteries

5.6.1. For most of the dry type batteries recharging is a practice that should
generally be avoided, as the cells are not designed for such use, and could be
hazardous in cells that are tightly sealed and not vented to permit the release of
gases that form during the charge and discharge. Most of the solid-electrolyte
batteries are labeled with a cautionary notice advising that they should not be
recharged.
5.6.2. Some special solid-electrolyte batteries with zinc-carbon cells can be
recharged for several cycles under carefully controlled conditions.
5.6.3. Due to the short shelf life after recharging of the dry type batteries, therefore
they should be returned to service soon after recharging.

6. OUTSTANDING MAINTENANCE POINTS ON BATTERIES.

6.1. Batteries and battery equipment should be kept clean, as impurities inside and
moisture outside the battery cause rapid self-discharge and deterioration.

6.2. Vent plugs should be free from obstruction to avoid internal gas pressure. Naked lights
or sparking near batteries shall ignite the emerging gases.
17
TSP-POGC-NIGC × T.T.F. Ø
SUBJECT BATTERY CODE
P/TM/TRG/E.BA/001

FIG.6

18
TSP-POGC-NIGC × T.T.F. Ø
SUBJECT BATTERY CODE
P/TM/TRG/E.BA/001

6.3. Electrolyte level should always be maintained above the cell plates and never allow it
go lower.

6.4. Mechanical damage follows the chemical changes that occur under maloperation of the
batteries.

6.5. Topping-up of the electrolyte is best to be done when the batteries are under
recharging or on float charge condition.

6.6. Only distilled and deionised water should be used for topping-up. Tap water should
never be used for topping up due to its impurities, which could be harmful to the batteries.

6.7. A periodic maintenance testing of the batteries is advised, to be carried out on the
equipment for which they are intended.

6.8. Separate hydrometers (to check the relative density) should be used for different types
of batteries, and each battery uses its own hydrometer to avoid contamination.

6.9. Battery connections and leads should be protected against moisture and corrosion by
using recommended Vaseline or petroleum jelly.

6.10. A thermometer, a recording logbook and a battery testing voltmeter should be

dedicated by the operators for the regular maintenance of the batteries.

6.11. Where both lead acid and alkaline (Ni-Cd) batteries are employed in a plant, it is best
to have separate battery rooms and under no account should an alkaline electrolyte be
added to a lead acid battery of vice versa.

6.12. Always ensure that the boxes and lids of the cells are thoroughly clean and dry.

6.13. The flat contact-making surfaces of the terminal pillars should be always cleaned
appropriately.

6.14. Do not scrape the surface of the battery leads and connectors because you may
damage the plating.

19
TSP-POGC-NIGC × T.T.F. Ø
SUBJECT BATTERY CODE
P/TM/TRG/E.BA/001

20
TSP-POGC-NIGC × T.T.F. Ø
SUBJECT BATTERY CODE
P/TM/TRG/E.BA/001

21
TSP-POGC-NIGC × T.T.F. Ø
SUBJECT BATTERY CODE
P/TM/TRG/E.BA/001

22
TSP-POGC-NIGC × T.T.F. Ø
SUBJECT BATTERY CODE
P/TM/TRG/E.BA/001

23
TSP-POGC-NIGC × T.T.F. Ø
SUBJECT BATTERY CODE
P/TM/TRG/E.BA/001

24
TSP-POGC-NIGC × T.T.F.
SUBJECT BATTERY CODE
P/TM/TRG/E.BA/001

25