EP Equipment EPT20-15ET, Service Manual

Page: 122 / 128

111
REV. 09/2016
SERVICE MANUAL - BATTERY
B
Battery Fault Analysis
Fault Negative Phenomena Cause Handling Methods
Electrode
plate sulfation 1. Battery capacity drops
during normal discharge
2. Density drops to be lower
than normal value
3. Voltage drops quickly when
discharging
4. Start charging under high
voltage
5. Bubbles generated during
charging
6. Coarse crystallization of
PbSO4 1. Insuf fi cient initial charge
2. Long time of storage under
the state of discharge
3. Long-term insuf
fi cient
charged
4. Electrolyte density is too high
5. Electrolyte level is too low,
the upper part of electrode
plate is exposed outside of
the electrolyte
6. Impure electrolyte
7. Internal short circuit
1. Over-discharge method
2. Repeated charging method
3. Water treatment method
Excessive
shedding
of active
substances 1. There is gray-brown
substance rising from the
bottom when charging
2. Battery capacity reduced 1. Brown precipitation is due to
excessive large charging
current
2. White sediment is due to
over-discharge
3. Battery electrolyte is impure 1. Clean up the precipitation
2. Adjust the density
3. Battery needs to be
replaced if necessary
Battery
overcharged 1. Color of battery fi lling cap
becomes yellow, and then
red
2. Battery casing deformation
3. Battery spacers
carbonization, deformation
4. Positive electrode corrosion,
broken
5. Electrode pole rubber
bushing raised, aged and
cracked
6. Frequent water-adding,
electrolytic turbidity during
charging
7. Evenly shedding of active
substances from electrode
plate
8. Positive electrode plate
detonation
1. Charger voltage and current
are set too high
2. Charging time is too long
3. Frequent charging
4. Less discharging, but much
charging
5. Charger failure 1. Adjust and repair the
charger
2. Adjust the charging system
3. Battery needs to be
replaced in severe situations
Battery Over-
discharge 1. Low static voltage
2. Electrolyte density is still
low after charging
3. Positive and negative
electrode plates curved or
fractured 1. Go on using the battery
despite of insuf
fi cient charge
2. Battery pack short circuit
3. Small current long time
discharge
1. Supplementary charging
2. Repair the vehicle
3. Battery needs to be
replaced in severe situations