Symptom
Rotten egg odor.
Possibly caused by
high temperature
environment,
overcharging,
excessively high
recharge
current,shorted
cells or a ground
fault or a combination
of these items.
Odor is a product of
extended thermal
runaway.
Replace the battery
system and correct the
items leading to the
thermal runaway.
Melted grease at
terminals.
Connections were
hot probably due
to excessive
resistance
caused by loose
connection, dirty
contact surfaces or
corrosion within the
connection.
Excessive voltage drop
perhaps leading to short
operating time or
damaged terminals.
In extreme case could
lead to melted terminal
and ignition of the
battery cover.
Clean and reassemble
the connection if
undamaged.
Replace any battery
with damaged terminals.
Corrosion at
terminals.
There is possibly
either residual
electrolyte from
manufacturing or
electrolyte leaking
from the battery
terminal seal
that is attacking the
interunit connector.
Increased connection
resistance and resulting
increase in the
connection heating and
voltage drop at high rate
discharge.
Disassemble connection,
clean, coat connecting
surfaces and terminal
area and seal with
antioxidation grease
and appropriately
reassemble the connection.
If leakage about the
terminal area is
obvious, the battery
should be replaced.
Burned area on
container.
Crack in container
wicking electrolyte
to grounded rack,
etc.
Ground fault.
Could result in personal
hazard due conductive
path to rack, etc.
Clear the ground fault
and replace defective
unit. Evaluate balance
of the string.
System float voltage
greater than 2.3 v/c
average at 77°F
(25°C).
Charger output set
incorrectly.
Overcharging will cause
excessive gassing and
drying of the electrolyte
and will contribute to
potential thermal
runaway.
Reset the charger
output voltage to the
recommended value.
Possible Causes
Possible Result
Corrective Actions
VISUAL BATTERY
CHECKS
TABLE 1-VRLA Battery Symptoms and Solutions (Continued)
41-7546/0213/CD 14 www.cdtechno.com
