Symptom
CAPACITY TEST
RESULTS
TEMPERATURE
CHECKS
Reduced operating
time at 77°F
with smooth voltage
decline.
Normal wear out
Eventual failure to
support the load
followed by potential
for shorted cells.
Replace battery system
when at 80% of rated
capacity or before.
Reduced operating
time at 77°F with
step voltage decline
or voltage plateaus.
Individual low
capacity cells.
Reversed cells during
discharge-reversed cells
will become very hot
and will not fully recharge.
Replace the isolated
low capacity batteries.
Excessive initial
voltage drop even to
the point of dropping
load in the first
several seconds.
Battery is cold.
Cabling is too small.
High resistance
connections.
Battery is undersized.
Shorted cells.
Excessive voltage drop.
Excessive voltage drop.
Cells will become hot,
could develop thermal
runaway; internal arcing
could result in explosion.
Heat the battery.
Run parallel cables.
Add required parallel
strings.
Replace isolated units
with shorts and evaluate
entire string.
Elevated battery
temperature.
Elevated room
temperature.
Inadequate cabinet
ventilation.
Discharge-Charge
cycle
AC ripple current
greater than 5
amperes
rms/100Ah battery
capacity.
Reduced life and
potential thermal
runaway.
Reduced life and
potential thermal
runaway.
Can be normal if not
exceeding 18°F (10°C)
increase.
Reduced life and
potential thermal
runaway.
Improve room air
conditioning.
Improve cabinet
ventilation and
temperature.
Limit recharge current.
Determine cause of
excessive AC ripple
current and correct.
Possible Causes
Possible Result
Corrective Actions
Elevated room
temperature.
Lack of adequate air
conditioning/ventilation.
Reduced battery life.
Cool the room or
accept reduced
battery life.
TABLE 1-VRLA Battery Symptoms and Solutions
41-7546/0213/CD 12 www.cdtechno.com
