Datasheet

12
Valve Regulated Lead-Acid Batteries
13
Valve Regulated Lead-Acid Batteries
1 | Precautions for Handling VRLA-Batteries
7. Treatment at Emergency
WARNING
(1) The batteries have toxic liquid - dilute sulfuric acid so-
lution in them. If the acid comes into contact with skin or
clothes, wash skin or cloth with lots of clean water to prevent
scalding from occurring. If the acid should come into con-
tact with the eyes, wash the eyes with lots of clean water and
consult a physician immediately to prevent possible loss of
sight.
CAUTION
(1) Check the batteries visually for any sign of irregularities in
appearance. If any damage exists such as cracks, deforma-
tion, leakage of electrolyte, or corrosion, the batteries must
be replaced with the new ones. Irregularities in the batteries
could result in bodily injury, electrolyte leakage, excessive
heat generation or explosion, if used. Furthermore, make
sure the batteries are clean and free from dirt and dust.
8. Storage
CAUTION
(1) Store the batteries in a fixed position separate from metal
or other conductive materials.
(2) Keep the batteries from rain water that could cause cor-
rosion on the terminals of the batteries.
(3) Keep the batteries right-side-up during transportation
and do not give any abnormally strong shock and jolt to the
batteries. Transporting the batteries in an abnormal posi-
tion or handling them roughly could destroy the batteries or
cause their characteristics to deteriorate.
(4) When storing the batteries, be sure to remove them
from the equipment or disconnect them from the charger
and the load, then store them at room temperature or lower
temperature. Do not store the batteries at direct sunlight,
higher temperature or high humidity. To do so cause the bat-
teries short life, performance deterioration or corrosion on
terminals.
REQUEST
(1) Charge the batteries at least once every twelve months
if they are stored at 20°C. Use the charge method specified
in “3. Preparation Prior to Use”. The interval of this charge
should be reduced to 50% by each 10°C rise in tempera-
ture above 20°C. The self-discharge rate doubles for each
10°C in temperature. If they are stored for a long time in
a discharged state, their capacity may not recover even
after charge. If the batteries are stored for more than a
year at room temperature, the life of the batteries may be
shortened.
(2) Store the batteries starting from the fully charged state to
prevent the life of the batteries being shortened.
(3) Use the batteries as quickly as possible after receiving
them as they gradually deteriorate even under proper storage
conditions.
9. Disposal and Recycling
CAUTION
(1) Please write the information about battery recycling on
the equipment, the package, the carton, the instruction
manual etc. in countries where legal or voluntary regulations
on battery recycling are applicable.
(2) Design the equipment such that exchange and disposal
of the batteries can be undertaken easily.
(3) Used batteries should be recycled. When returning used
batteries, insulate their terminals using adhesive tape, etc.
Even used batteries still have electrical charge and an explo-
sion or a fire may occur, if proper insulation is not given on
the terminals of the used batteries.
2 | General Information
1. Battery Construction
Positive plates
Positive plates are plate electrodes of which a grid frame of
lead-tin-calcium alloy holds porous lead dioxide as the ac-
tive material. The magnification of a positive active material
is shown on following figure (1).
Negative plates
Negative plates are plate electrodes of which a grid frame of
lead-tin-calcium alloy holds spongy lead as the active mate-
rial. The magnification of a negative active material is shown
on following figure (2).
Electrolyte
Diluted sulfuric acid is used as the medium for conducting
ions in the electrochemical reaction in the battery. Some ad-
ditives are included to keep good recovery performance af-
ter deep discharge.
Separators
Separators, which retain electrolyte and prevent shorting
between positive and negative plates, adopt a non-woven
fabric of fine glass fibers which is chemically stable in the
diluted sulfuric acid electrolyte. Being highly porous, sepa-
rators retain electrolyte for the reaction of active materials
in the plates. Typical magnification of separator is shown in
following figure (3).
Vent (One way valve)
The valve is comprised of a one-way valve made of material
such as neoprene. When gas is generated in the battery un-
der extreme overcharge condition due to erroneous charging,
charger malfunctions or other abnormalities, the vent valve
opens to release excessive pressure in the battery and main-
tain the gas pressure within specific range (7.1 to 43.6 kPa).
During ordinary use of the battery, the vent valve is closed to
shut out outside air and prevent oxygen in the air from react-
ing with the active material in the negative electrodes.
Positive and negative electrode terminals
Positive and negative electrode terminals may be faston tab
type, bolt fastening type or threaded post type, depending
on the type of the battery. Sealing of the terminal is achieved
by a structure which secures long adhesive-embedded paths
and by the adoption of strong epoxy adhesives. For specific
dimensions and shapes of terminals, see page 23.
Battery case materials and the design
Materials of the body and cover of the battery case are ABS
resins, unless otherwise specified. Since the inside of VRLA
battery is pressurized and depressurized, stress occurs at
the container and cover. The design according to the stress
is designed to accommodate the fluctuations in stress in the
event the battery becomes deformed. The thickness of con-
tainer, form, material and stress analysis are determined by
utilization of computer aided engineering (CAE). This depicts
the container deign & strength. Destructive examinations us-
ing the molded container are also carried out. In other cases
in which water in electrolysis liquid may penetrate through
container in service life, the container design is put through
Fig. 1 Magnification of positive active material
Fig. 2 Magnification of negative active material
Fig. 3 Typical magnification of separator