Guide to VRLA Batteries

5
One of the major disadvantages of nickel-cadmium (ni-cad)
b
atteries is that after shallow discharge cycles, the unused
portions of the electrodes “remember” the previous cycles
and are unable to sustain the required discharge voltage
beyond the depth of the previous cycles. The capacity is
lost and can only be restored by slowly discharging com-
pletely (generally outside the application), and properly
recharging. VRLA lead-acid batteries do not exhibit this
c
apacity
robbing effect known as memory.
What are the safety precautions
for VRLA batteries?
Although all valve-regulated batteries have the electrolyte
immobilized within the cell, the electrical hazard associated
with batteries still exists. Work performed on these batteries
should be done with the tools and the protective equipment
listed below. Valve-regulated battery installations should be
supervised by personnel familiar with batteries and battery
safety precautions.
Protective Equipment
To assure safe battery handling, installation and maintenance,
the following protection equipment should be used:
n
Safety glasses or face shield (Consult application
specific requirements)
n
Acid-resistant gloves
n
Protective aprons and safety shoes
n
Proper lifting devices
n
Properly insulated tools
Procedures
Consult user manual of specific application for safety &
operating requirements. The following safety procedures
should be followed during installation: (Always wear safety
glasses or face shield.)
1. These batteries are sealed and contain no free flowing
electrolyte. Under normal operating conditions, they do
not present any acid danger. However, if the battery jar,
case, or cover is damaged, acid could be present.
Sulfuric acid is harmful to the skin and eyes. Flush
affected area with water immediately and consult a physi-
c
ian if splashed in the eyes. Consult MSDS for additional
precautions and first aid measures.
2. Prohibit smoking and open flames, and avoid arcing in
the immediate vicinity of the battery.
3. Do not wear metallic objects, such as jewelry, while
working on batteries. Do not store un-insulated tools in
pockets or tool belt while working in vicinity of battery.
4
. Keep the top of the battery dry and clear of all tools and
other foreign objects.
5. Provide adequate ventilation as regulated by Federal,
State and Local codes and follow recommended
charging voltages.
6. Extinguishing media: Class ABC extinguisher. Note: CO
2
may be used but not directly on the cells due to thermal
shock and potential cracking of cases.
7. Never remove or tamper with pressure-relief valves.
Warranty void if vent valve is removed.
Can VRLA batteries be installed
in sealed battery boxes?
NO! Never install any type of battery in a completely sealed
container. Although most of the normal gasses (oxygen and
hydro gen) produced in a VRLA battery will be recombined and
not escape, oxygen and hydrogen will escape from the
battery in an overcharge condition (as is typical of any
type battery).
These potentially explosive gasses must be allowed to vent
to the atmosphere and must never be trapped in a sealed
battery box or tightly enclosed space!
Does depth of discharge affect cycle life?
Yes! The harder any battery has to work, the sooner it will fail.
The shallower the average discharge, the longer the life.
It’s important to size a battery system to deliver at least twice
the energy required, to assure shallow discharges.
Follow these tips for the longest life:
DANGER
!
SHIELD EYES
EXPLOSIVE GASES
CAN CAUSE BLINDNESS
OR INJURY.
NO.
• SPARKS
• FLAMES
• SMOKING
SULFURIC
ACID
CAN CAUSE
BLINDNESS OR
SEVERE BURNS.
FLUSH EYES
IMMEDIATELY
WITH WATER.
GET
MEDICAL
HELP
FAST.
HIGH
VOLTAGE...
RISK OF SHOCK.
DO NOT TOUCH
UNINSULATED
TERMINALS OR
CONNECTORS.
DO NOT REMOVE VENT VALVE.
WARRANTY VOID IF VENT VALVE IS REMOVED.
VENTILATE WELL WHEN IN AN ENCLOSED
SPACE AND WHEN CHARGING.
REPAIR SHOULD BE PERFORMED ONLY
.BY A QUALIFIED SERVICE TECHNICIAN.
SEE INSTALLATION, MAINTENANCE AND OPERATION
INSTRUCTIONS FOR IMPORTANT SAFETY PRECAUTIONS.
Batteries, battery posts, terminals and related accessories
contain lead and lead compounds, and other chemicals known
to the state of California to cause cancer and birth defects or
other reproductive harm. Wash hands after handling.
California
Proposition 65
Warning