Environment Ambient and
Battery Temperature
While the VRLA battery will function at extremes
of temperature, it is rated at 77°F (25°C) and the
ideal operating temperature range for the 10
Year VRLA battery is 70°F (21°C) to 80°F (27°C).
Operation at cooler temperatures will reduce the
anticipated standby operating time while
operation at warmer temperatures will detract
from the battery life and will increase the
potential of a thermal runaway condition.
The battery will experience a 50% reduction of
life for each 18°F (10°C) above 77°F (25°C).
High ambient room temperature should be corrected
through the use of appropriate ventilation and air
conditioning.
The VRLA battery should not be charged at
temperatures exceeding 122°F (50°C). A thermal
runaway condition could result.
The individual batteries within the string should
not exceed the ambient temperature by more
than 18°F (10°C). If the entire battery or individual
units temperatures are excessively high, the
respective units may be experiencing thermal
runaway. In this situation the charging current
should be terminated by disconnecting the
Charger/Rectifier and the cause of the situation
should be determined and corrected.
If thermal runaway has occurred, the battery
system should be capacity tested and replaced
if necessary.
Battery Visual Inspection
Container Cleanliness
It is important that the individual batteries be
clean and properly spaced. An accumulation
of dirt or dust and moisture on the covers can
produce a conductive path between the
terminals or to ground which could result in
short circuits or ground faults.
When batteries are cleaned, they should be on
open circuit. For cleaning, use a cloth moistened
in a solution of bicarbonate of soda and water.
Do not use cleaners of unknown solutions such
as window or glass cleaners and solvents. Use of
certain petroleum based cleaners will damage the
battery plastic containers and could cause them
to crack and craze.
Container and Cover Damage
Should a crack or other penetration of the
container or cover of a battery be noted, it should
be replaced. A crack in the container could allow
conductive electrolyte to wick from the battery and
create a ground fault. A ground fault could lead to
melting and burning of the container.
A hole in the cover, even without wicking of the
electrolyte, can also be a serious situation.
The hole will allow drying of the electrolyte in the
subject cell resulting in an eventual high resistance
and heating of the subject cell.
Containers which are severely swollen and
permanently deformed have been overheated and
experienced thermal runaway. Thermal runaway
will also cause the batteries to gas and dry out
and will damage the plates. In this case the entire
battery string should be replaced.
Terminals
Bent or otherwise damaged terminals can
produce high resistance connections or can
hide a fracture that could fuse open under load.
Batteries with damaged terminals should be
replaced.
If the protective grease at a termination has
melted and flowed onto the cover, it is an
indication that the connection has been hot and
this is, in all probability, the result of a loose or
high resistance connection. In this situation the
connection should be disassembled, inspected
for damage, cleaned and properly reassembled.
41-7546/0213/CD 7 www.cdtechno.com
