Foton Series Light Bus. Service Manual — part 16
OPERATION AND MAINTENANCE MANUAL FOR FOTON VIEW SERIES LIGHT BUS
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Chapter 11 Structure, Application and Service of
Electrical Devices & Instrument
11.1 Electrical System Overview
The rated voltage for electrical devices on BJ6536 series of light bus is 12V. Single wire system is adopted
for the circuit of electrical devicess, with negative grounding. The circuit for the complete vehicle is composed of
three major harnesses. Front panel harness is wired inside the cab; body harness is located inside engine
compartment; and chassis harness is arranged inside the frame. The insertings of front panel instrument harness
and chassis harness must be dismantled before cab is to be disassembled.
Most electrical fittings and harnesses are connected with plug connector except very few of them jointed with
bolts, which is beneficial to inspection and maintenance. It is not allowed to randomly change the positions of
plug during use, so as to ensure the reliability and safety of the circuit. All the circuits are fitted with fuses. The
fusible link is designed to protect the vehicle circuit, it breaks when circuit current becomes high. Fusible link
should be replaced after a fault has been removd. It is not allowed to use other metal conductor as fuse.
Refer to the diagram for connection of vehicle electrical devices (See the electrical wiring diagram attached
to this book).
11.2 Fuse Box
Fuse box integrates multiple electrical connections in one place to facilitate easy check and service on
vehicle electrical devices. Refer to the indication diagram and parameters on fuse box cover to locate the wiring of
each device and perform service. Use of other electrical fittings beyond specfication is not allowed..
11.3 Troubleshooting
If faults are noticed during driving and sevice check, operator can pinpoint fault locations according to
electrical diagram, performs service or replacement. Never change connector location at random or connect wrong
wire. Fault check starts with the most convenient place, and places where faults frequently happen such as
bulb/fuse, and plug-in connectors..
11.3.1 Gasoline Engine Failure Startup
Use elementary diagram to remove gasoline engine fault. Here are some typical faults during startup:
(1) While ignition switch is set to START, cannot hear starter electro-meganetic switch clicking and starter
rolling..
(2) Electo-magenetic clicking is heard, but starter does not run.
(3) Starter begins to roll, but engine does not start up.
(4) Hear continious clicking sound.
Analysis:
1. No starter switch clicks when ignition switch is set to “START”. Check if battery is connected. If battery
is connected, test ignition switch and start relay power outputs. Repair or replace ignition switch or relay if there
is power, otherwise test starter power connector. If the connector is hot, it indicates that starter switch attracts coil.
Repair the starter.
2. When ignition switch is set to “Start”, starter electro-magnetic switch clicks but starter does not run. This
indicates there is no continuity at starter due to burntout or dirty main contacts. Adjust starter switch travel and
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remove dirt on main contact.
3. When ignition switch is set to “START”, starter begins to run but engine does not start up. One cause
may be that starter small gear runs at high speed earlier before it meshes with flywheel gear ring due to wrong
switch travel. Adjust switch travel. Another cause may be that starter non-return clutch is damaged. Repair or
replace starter.
4. When ignition switch is set to “START”, starter clicks continiously. The cause may be
a)Starter rotator is short circuit. Repair or replace rotator;
b)Battery is low.
To test above two symptoms, press horn while key is at “Start”:
a)If horn works well or sound a little bit lower than usual, it indicats that battery is full, click sound is due to
rotator short circuit.
b)If horn does not work or its sound is much low, it indicates that battery is low. Recharge battery.
11.3.2 Faults -- alternator, regulator and indicator
Refer to elementary diagram to check faults on alternator, regulator and indicator..
Analysis:
Check failure alternator. While power supply to whole vehicle is normal and ignition switch is set to “ON”
position, check the indicator light first. Turn indicator light bracket behind the instrument panel by 90º to remove
it. If the bulb is in good condition, re-mount it to proceed to further check. Open the fuse box and check the fuse
for power supply. If the fuses look good, use a multimeter to test resistance. If the circuit connection of indicator
light in here is good, the indicator light should be on. If an open circuit is found, turn to check harness at vehicle
body or on front panel and alternator. Perform service if any bad contact or open circuit if found. When ignition
switch is on “ON” position, the alternator indicator light should be on. But if the indicator light keeps on after
starter has been started and alternator has been running at 100r/min or above, it indicates that the alternato is in
trouble or the built-in voltage regulator has been damaged. In this case, alternator should be repaired or replaced.
11.3.3 Headlight faults diagnosis
Refer to the elementary diagram analyze headlight faults.
Analysis:
1. Low beam faults
Set headlight switch to Hi-beam, toggle Dim switch. Hi-beam is on while Lo- beam is off, Probe test Lo-
beam output at combined DIM switch, if it is not hot, it indicates poor contact at DIM switch or wire dewelded. If
the switch is hot, it indicates no continuity at headlight plug-in connector, Lo-beam fuse burntout or bulb failure.
Repair or replace.
2. High beam faults
When headlight switch is set to Hi-beam, no high beam when toggling switch dim switch. To test this, first
set headlight switch to “0” position, slowly lift combined switch handle, turn on “flash to pass” switch to see if
high beam is on:
→(yes)→no continuity at DIM switch→repair or replace dim switch
→(no, and hi-beam indicator on dashboard is also off)→hi-beam output wire de-welded, cut off or poor contact
→(no, but hi-beam indicator on dashboard is on)→check fuse on fuse panel
→(fuse is ok but fuse post is not hot)→light relay damaged→repair or replace.
3. Check PASS light switch
While headlight switch is off, toggle PASS light switch, hi-beam is off. To test this, set headlight switch to
Hi-beam, lift combined switch handle to trun on DIM switch. If hi-beam is off, control circuit and light relays may
be the cause. If hi-beam is on, PASS light switch may be failure.
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11.3.4 Faults diagnosis -- corner light, taillight and fog light
Please refer to the elementary diagram for analysis of faults of front corner light, taillight, and fog light.
Analysis:
A.
While switch is set to “Lo-beam”, corner light is off, probe test the continuity of corner light ouput:
→(not hot)→repair or replace switch
→(hot)→broken bulb, poor contact
B.
While switch is set to “Lo-beam”, corner light is on but taillight is off. Check harness connection at
ceiling and taillight plug. If they are all ok, failure bulbs or poor contact may be the cause.
C.
While switch is set to “Lo-beam”, fog light is off. Probe test fog light switch:
→(not hot)→fog light poor contact
→(hot)check bulb and two plug connectors
→remove faults
11.3.5 Faults diagnosis --
Please refer to elementary diagram for diagnosis of faults.
Analysis:
Set ignition switch to “ON”, toggle switch to “LEFT”
If : LF- light is off→check bulb and plug
LF-light is on but LR light is off→check bulb for de-welding, wrie cutoff.
LF/LR light are off→turn on emergency switch
→if lights are all on→L-switch failure
→if lights are all off→emergency switch poor contact or flash relay failure
and if: Left is on but indicator on dashboard is off→check indicator and dashboard plugs
Same measures are applied to RF, RR s.
11.3.6 Faults diagnosis – windshield wiper circuit
According to diagram to check windshile wiper circuit. While vehicle power supply is normal, turn on wiper
switch. If wiper does not move, check if wiper fuses are burnt out or wiper motor 4-lead plug is connected. If all
works well, turn to check wiper switch output line. Locate faults and remove them. If motor does not run after
ciruit faults have been removed, the cause must be on motor. Repair or replace motor.
11.3.7 Fault diagnosis – i
nstrument panel indicator circuit
Refer to the elementary diagram to diagnose instrument panel indicator circuit
Analysis:
a) Oil pressure indicator keeps off
Check bulb for damage →(ok)→bulb socket continuity→(ok)→ground short oil pressure sensor lead:
if: indicator lits→sensor damaged
indicator is still off →check continuity between harness at chassis behind front fender and engine
compartment harness.
It can also probe to test continuity at indicator’s positive side, if there is no power supply, meter’s print
circuit or plug may be the cause.
b) Oil pressure indicator keeps on
If pressure indicator keeps on after engine has started. Disconnect sensor lead:
if: indicator is till on→indicator’s circuit grounds
indicator turns off→check oil pump performance and any restriction in oil pipe
c) Coolant temperature meter faults
According to elementary diagram to analyze faults. Follow circuit to check if sensor or meter head causes the
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fault. Typical faults in this case are: damaged sensor, meter head is stuck or lead is disconnected. Their solutions
see “Coolant temperature meter and sensor” in 18.5 (“Complex meters and auxiliary electrical devices3①”.)
d) Fuel meter faults
Solutions see “Fuel meter &sensors” in 18.5 (“Complex meters and auxiliary electrical devices” 3②.)
During the process, never scratch on fuel tank to check after sensor’s float has been removed.
11.3.8
Troubleshooting for other e
lectrical devices and curcuits
BJ6536 series light buses also equip with other assemblies such as CD/Radio/Cassette player, central lock,
back-up radar, washer, horn, brake lights, top lights, back-up lights buzzer, heating unit&A/C. By refering to their
elementary diagrame, opeartor can locate their connector positions, find fault one by one and remove them.
Only professional or trained technician can repair CD/Radio/Cassette player and A/C system
Back up radar is a kind of vehicle back-up assisting device. It contains sensor, display, controls and circuit. It
is used to detect any obstacles within the range of 0.9-0.3m right behind vehicle. At the moment obstacle is less
than 0.3m to vehicle, it triggers system is to alarm. Display shows approaching distance (cm), obstacle’s position,
alarm sound frequence change etc.
Summery: Fault checks stated in this section are only regular check procedures. Things are more complicated
in real world. Pratically, operator should watch how and when faults happen, then carefully makes reference to
diagram and knowledges on devices controlling relations. Check should start with the simplest one. This will
make fault-removing much quicker.
11.4 Electrical devices
11.4.1 Battery
BJ6536 series light bus uses dry load battery. In emergent case, it could fill formulated electrolyte into
battery after the electrolyte has been laid for 30 minutes, but battery normally has to be charged for 3~5 hours
before use. Battery has been charged for 4 hours before delivery from factory.
1. Structure, Parameters and Performance
S/N
Description
Parameter
1
Model
Negative ground
2
Number of batterie cell
6
3
Rated Voltage (V)
12
4
Rated Capacity (V/A-h)
12/60 (BJ491EQ1)80(4D22)
5
Fluid level height above pole plate (mm)
10~15
6
Exterior dimensions (L × W× H) (mm)
254.4×164×220
7
Specific Gravity of Electrolyte
Table 11-1 Specific Gravity of Electrolyte for Different Regions and Temperature (g/cm
3
)
Specific Gravity of Electrolyte at 15
for Fully
℃
Charged Battery
Climatic Condition
Winter
Summer
Region where temperature is lower than -40℃ in winter
1.31
1.27
Region where temperature is above -40℃ in winter
1.29
1.25
Region where temperature is above -30℃ in winter
1.28
1.25
Region where temperature is above -20℃ in winter
1.27
1.24
Region where temperature is above 0℃ in winter
1.24
1.24
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Table 11-2 Corrected Values of Temperature and Specific Gravity of Electrolyte
Measured Temperature of Electrolyte
+45
+30
+15
0
-15
-30
-45
Corrected Value of Readings from Gravimeter
+0.02
+0.01
0
-0.01
-0.02
-0.03
-0.04
2. Use of battery
(1) Preparation of electrolyte: Standard sulfuric acid and distlled water are to be used.
① Lead-acid battery electrolyte is made up of distalled water and concentrated sulfuric acid, and the density
of electrolyte in a battery that is used for starting up a vehicle is 1.280±0.005g/cm
3
(25℃).
② The container used to prepare electrolyte must be glazed ceramic, glass fibre reinforced plastic, plastic
tank, or lead-lined wood tank that have higher acid and temperature tolerance. Operator must wear protective
articles during the process.
③ Rinse and clean the container prior to preparation with clean water.
④ Pour purified water into the container first, then fill slowly concentrated sulfuric acid into purified water
while keep stiring. Never do this other way round avoid explosive splashes.
The conversion formula is d25=dt+0.0007(t-25)
d25 : Density of electrolyte at 25℃ dt: Density of electrolyte when temperature is t
0.0007 : Temperature Coefficient t: Actually Measured Temperature of Electrolyte
The proportion of purified water (or distilled water) and sulfuric acid in electrolyte is shown in the following
table.
Table 11-3 Proportion of Purified Water (or Distilled Water) and Sulfuric Acid in Electrolyte
Specific Gravity of Electrolyte at
0℃ (g/cm3)
Volume Ratio of Purified Water (or
Distilled Water) and Sulfuric Acid
Weight Ratio of Purified Water (or
Distilled Water) and Sulfuric Acid
1.10
9.80:1
6.28:1
1.11
8.80:1
5.84:1
1.12
8.00:1
5.40:1
1.13
7.28:1
4.40:1
1.14
6.68:1
3.98:1
1.15
6.15:1
3.63:1
1.16
5.70:1
3.35:1
1.17
5.30:1
3.11:1
1.18
4.95:1
2.90:1
1.19
4.63:1
2.52:1
1.20
4.33:1
2.36:1
1.21
4.07:1
2.22:1
1.22
3.84:1
2.09:1
1.23
3.60:1
1.97:1
1.24
3.40:1
1.86:1
1.25
3.22:1
1.76:1
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Specific Gravity of Electrolyte at
0℃ (g/cm3)
Volume Ratio of Purified Water (or
Distilled Water) and Sulfuric Acid
Weight Ratio of Purified Water (or
Distilled Water) and Sulfuric Acid
1.26
3.05:1
1.60:1
1.27
2.80:1
1.57:1
1.28
2.75:1
1.49:1
1.29
2.60:1
1.41:1
1.30
2.47:1
1.34:1
Remark: This table is calculated based on a 1.83 specific gravity of pure sulfuric acid at 20
.
℃
(2) Fill fluid
① Exhaust bolt, make sure to penetrate the riser vent on the exhaust bolt, as there is gasket and sealing paper
underneath it, to be removed after acid has been filled.
② Electrolyte must be cooled down to below 30℃ before filling.
③ Fluid level for plastic case battery aligns with “MAX” line, and that for electrolyte in rubber case is higher
than partition board by 10~15mm.
④ Tighten vent plug to prevent fluid leak.
3. Charge a battery
(1) Charging device
DC power supply must be used to charge a battery. AC must be converted into DC before charging.
① Rectifier
Solid rectifiers such as cupric oxide rectifier, selen rectifier, and silicon rectifier, as well as gas filled valve
rectifier (tungsten rectifier) and mercury rectifier are commonly used. Their input AC voltage is generally 110V or
220V, and the nominal voltage of output is 6V, 12V, and 24V. Solid rectifiers have been widely applied as they are
easy to use and no service is needed during charging.
② Controllable silicon voltage regulating charger
As the number of batteries in serial is varied, voltage is to be changed during charging process to control the
charging current. Therefore, it is required to use DC power source as its voltage can be regulated. Though silicon
rectifier is comparatively light and easy to move, it still needs rather cumbersome voltage transformer.
Controllable silicon voltage regulating charger can be adopted to overcome the above-mentioned shortage. One
kind of 8kw controllable silicon voltage regulating transformer in the market uses a power supply of 220V AC, to
be converted into DC through the controllable silicon rectifier, and charge the battery from its output end, with a
0~220V DC output voltage and a 0~40A current.
(2) Detecting Instrument
Densimeter, thermometer, voltmeter, and ammeter, as well as other testing instruments and necessary tools
are generally required for battery charging and routine maintenance.
(3) Battery charging
① Preparation prior to charging
Check and measure if electrolyte or purified water complies with regulations. Remove vent plug on battery,
and add fluid or replenish water to the maximum level line.
② Connection for charging
The charger positive is to be connected with battery positive, and negative to negative. Make sure not to
connect them reversely. Charging connections must be secured.
③ Charging Mode
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There are normally three kinds of charging types as constant current, constant voltage and quick charging..
Constant current charging: including initial charging, supplementary charging, general charging and
equalizing charging.
▲ Initial charging: Initial charging is the first-time charging on a new non-dry load battery. After non-dry
load battery has been filled with electrolyte, it is to be laid for 1~6 hours. Start charging when fluid temperature
has cooled down to below 35℃. The current for initial charging is generally 0.07C20A, and when single frame
voltage has charged to 2.4V, go on charging with half of the current.
▲ Supplementary charging: Supplementary charging is applied to the dry-load battery that has been
stored for a long time with rather poor dry-load electrical performance, or the battery that has been laid for about
one month after it was filled with acid and charged. The current for supplementary charging is 0.1C20A, and the
time duration for supplementary charging is 5 hours or so, or the charging duration is to be determined based on
the length of storage.
▲ General charging
General charging means the charging after the battery has been used after initial charging. 0.1C20A is applied
for the 1
st
stage of general charging, it charges the battery for 8~12 hours until the voltage has risen to more than
2.4V/single frame, then go on chargingd for another 10 hours at halved current. The charging power rate is
generally more than 1.5 times that of the discharging rate, or 1.3~1.5 times that of the rated charging capacity.
▲ Equalizing charging
It is to fully charge the battery with general charging method, and then to charge it with 0.035 C20A current.
When battery emits uniform air bubble and temperature has risen, stop charging for one hour. Repeat it for 3~4
times the same way, so that each single battery can give out large amounts of air bubble. Finish charging when
voltage of battery and density of electrolyte have tended to be stable.
▲ Constant voltage charging:
Constant voltage charging is to charge the battery with a constant voltage. At beginning the charging current
is relatively larger, and then it is reduced gradually. The voltage for constant voltage charge generally remains
during 2.3~2.4V. Very few evaporation occurs with such a method, and therefore, the constant voltaging charge is
often applied to maintenance-free sealed lead-acid batteries.
▲ Quick charging:
Large current and impulse are applied for quick charging. It uses intermittent charging method with short
period discharging to charge a battery. 1~2 times C20A large current is used for quick charging. Quick charging
proceeds with tailor-made quick charger.
▲ Signs of a fully charged battery
Large amounts of air bubbles are generated in battery single frame. Battery individual voltage ranges during
2.6~2.8v, and the value can remain unchanged for more than two hours.
▲ Notes to battery charging
Fluid temperature shall not exceed 45℃, otherwise cooling measures should be taken (to reduce charging
current or stop charging or cool down in water tank), for ventilation to be nice and fire source to be forbidden.
▲Check and assess a faulty lead-acid battery
Table 11-4 Specific Gravity Measurement
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S.G. Value (25℃)
Assessment
Treatment
More than 1.300
Concentration of electrolyte is too
high, incorrect fluid filling.
Use ion wate to adjust.r
1.250~1.280
Good
1.250~1.220
Not fully charged
Supplementary charging
Lower than 1.220~1.100
Overdischarging, concentration is too
low
Check after charging
More than 0.04 difference in specific
gravity among frames
Certain single frame is faulty
Check after charging
Table 11-5 Voltage Measurement
Voltage
Assessment
Treatment
More than 12.5V
Normal
12.5~11.5V
Not fully charged
Supplementary charging
Lower than 11.5V
Over dischargeing or internal failure
Check after charging
Table 11-6 Capacity Measurement
Display on Volume Meter
Assessment
Treatment
White Zone
Fully charged
Green Zone
Normal
Yellow Zone
Re-charging
Supplementary charging
Red Zone
Fully discharged
Check after supplementary charging
4. Common failures, cause analysis, and failure removal for lead battery
(1)
Why does a full battery lose its power after being laid for long?
A full battery will lose its power after being shelf-stored for long. This is called “self-discharging” process.
Battery material purity is the main cause of self-discharging. There are impurities in battery plates and electrolyte,
they makes potential difference (PD) among impurities itselves or between impurities and plates. This could form
a “partial current” loop that makes battery discharging.
As perfectly pure material will never be available, and battery plate/metal seperator also constitutes battery
cell, slight self-discharging is inevitable. But use battery wrongly will accelerate self-discharging. When
electrolyte iron content is over 1%, battery will be discharged completely overnight. Electrolyte splashes on
battery cover will also trigger self-discharging once they connect battery terminals. Longer shelf-stored battery
will let acid sink to bottom, creating PD between plate top and bottom that makes battery self-discharging.
To correct a seriously self-discharged battery, one can let it discharge completely. That is to encourage
impurities to enter electrolyte. Then remove electrolyte, wash battery with distilled water. After being filled with
new electrolyte and recharged, the battery can work again.
(2) What is sulfuration of battery? And what is the cause?
Battery sulfurization refers to coarse crystals (lead sulphate) layer on battery plate. These coarse crystals
block seriously cavities on plate to reduce battery capacity. Crystals have very low conductivity, they increases
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battery internal resistance, making battery unable to provide enough current to starter to crank engine. Besides,
crystals cannot dissolve in electrolyte even in normal recharging process. Serious sulfurization kills a battery.
The main causes of sulfurization lay to: A.repeated short recharging for longer time and longer battery
shelf-storing time after being discharged. In these two cases, lead sulphate will re-crystalized due to temperature
change. B. Battery level is too low, larger plate area is exposed to air to make oxidization happening (especially
for negative plate); C. during vehicle’s driving, electrolyte contacts oxidized section on plate, creating hard layer
of lead sulphate that sulfurizes upper part of the plate. Besides, much higher electrolyte gravity, impure electrolyte
and abrupt temperature change are also the causes.
To cure these, one should always keep battery full; recharge drained battery within 24 hours; keep proper
fluid gravity and level. Slightly sulfurized battery can be recharged with over-charging method, and serious one
with de-sulfurizing charging method.
(3)
What will happen after battery plate has sulfurized?
There are several abnormal symptoms such as: single cell end voltage drops sharply (testing with high
sensitive discharger); early “boiling” during recharging while electrolyte gravity increases slowly (even no
change); electrolyte temperature increases sharply.
(4) How to prevent plate from sulfuration ?
① Do not lay a half –discharged battery too long, and keep battery full all the time.
② Maintain fluid level is 10-15mm above plate, add distilled water if necessary
③ Do not over discharge a battery.
(5) How to fix a sulfurated battery?
① Prolonged recharging with low current can cure slightly sulfurized plate. That is to recharge continuously
by second stage current after first recharging till bubbles are seen in electrolyte and electrolyte gravity reaches
around 1.280.
② Seriously sulfurized plate can be cured by “water treatment”. When a battery’s discharge capacity reaches
80% of its rated capacity, the treatment is basically done. Otherwise repeat above process till battery restores its
performance.
(6)
Why are there short-circuit happening inside battery?
How to fix it?
①Inferior or or defected separator plate. They let battery paste (active media) penetrate the plate to connect
two (+ -) poles.
②There are heavy sheddings on the bottom. It conducts plate lower edge to make short circuit.
③Higher charging or discharging current makes plate warped, or conductive objects drop into battery to
make short circuit.
Open battery to check once there is short circuit inside. Change plate if it is defect or has cavities; remove
battery paste sediments; and press warped plate into flat.
(7)
What is it like when plate short circuit happens?
The main symptom is: low voltage in open loop with small capacity. Single cell end voltage drops to zero
quickly by testing with high sensitive discharger. And end voltage and electrolyte gravity raise very slow during
charging process. There are few or even no bubbles at later charging stage.
(8)
Why does battery plate become warped?
The main symptom is: low voltage in open loop with small capacity. Single frame end voltage drops to zero
quickly by testing with high sensitive discharger. And end voltage and electrolyte gravity raise very slow during
charging process. There are few or even no bubbles at later charging stage.
①Poor quality. At the time a battery is made, the manufacturer did not Lead-galvanize plate evenly, paste
grown on plate also distributes unevenly. Therefore, chemical reactions happen on plate vary on each section, and
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plate expensing and shrinking rate also differ. All these make plate warped or even cracking.
②Frequent high voltage discharging; different current density on each section of plate; and paste’s different
expansion rate make plate warped.
③Excessive discharging makes lead sulphate growing in the depth of plate, recharging cannot help to restore.
The internal expansion occurred also makes plate warped.
(9)
Why are there so much plate shadding?
Shadding happens mainly on positive plate. Paste’s size keeps changing during charging and discharging. It
is normal and inevitable to see they peel off from plate. But use battery wrongly will accelerate this process, these
wrong doings include:
① Higher recharging voltage increases electrolyte temperature; paste expands and softens to peel off.
② Over charge battery frequently. Great amount of air escapes from plate cavities to form pressure to press
paste to peel off.
③ Higher discharging current, prolonged connection to starter and warped plate also accelerate paste to peel
off.
④ Unable to charge battery timely in winter, electrolyte gravity becomes low and electrolyte freezes.
⑤ Battery has subjected to strong shock while vehicle is driving.
(10)
What is the cause of polar reverse in a centain frame?
The causes: the capacity of this frame reduces due to fault or other reasons. While discharge is in progress,
low capacity cell discharges to zero first, discharge current from other cells will come to charge this cell. This will
reverse this frame’s poles (+ ←→ ―).In a battery with 3 frames, if one of them reverses its pole, battery’s end
voltage value will be 2V rather than 6V (tested with voltmeter).
To prevent this from happening, one should maintain battery carefully, and keep watching closely all the time
to notice faults early. For any low capacity charge or discharge separately any frame of low capacity or replace
frame plate until its capacity approaches or equal to other normal cell’s capacity.
(11) Why will battery blow up?
Battery blow-up mainly happens when a battery is over-charged, during which water in electrolyte
decomposes into hydrogen and oxygen with great amount of bubbles. Other causes include: internal short-circuit,
extrem sulfurization. When a battery is being recharged, electrolyte temperature will increase sharply, the process
evaporates humidity in great amount. In the case battery fluid filler hole is restricted to block excessive gas to
escape, battery will blow up when internal pressure reaches to centain level (or ignited by spark). Precautions
include:
① Always keep vent hole on filler cover cleared;
② Keep connections on terminals tighten to avoid spark;
③ Open filler cover first when tested with high sensitive discharger;
④ Do not charge battery excessively to reduce gas production. There should be no lighted fire around
charging chamber and be sure to keep good ventilation.
(12)
Why will battery fluid level lower quickly?
Water evaporation and electrolysis process during recharging can lower the fluid level. One should check
fluid level every 5-6 days in summer and 10-15 days in winter. If fluid level lowers too quickly, the cause may be
higher charging current, one should adjust charging system.
(13)
What is the cause to make fluid level in a frame lowering quickly?
Cracked case or damaged sealing may be the causes. In the event case and seal are all well, the cause may lay
to short circuit or sulfulrization in this cell. While there is short circuit or sulfurization happening, temperature
will go up quickly during recharging. This process overheats electrolyte to prompt water evaporation. When a
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OPERATION AND MAINTENANCE MANUAL FOR FOTON VIEW SERIES LIGHT BUS
·242·
plate has sulfurized, the early “boiling” during recharging will also lower fluid level.
(14)
What should be added when fluid level lewers, distilled water or electrolyte?
Add distilled water when fluid level lowers. It is water evaporation and water electrolysis (happened when
discharging is almost finished) that lowers the level. Add electrolyte will increase fluid gravity, shortening
battery’s life span. In the case broken battery case makes fluid leaking, one should repair the case before adding
formulated electrolyte.
(15)
How to test battery’s remaining capacity?
There are two methods in general:
①Test eletrolyte gravity with hydrometer, as gravity in charged battery increases and reduces in discharged
battery. Gravity will help to judge how much power remained in a battery. Experience tells that 6% discharing rate
equals to every 0.01g/cm gravity reduction. When a full battery’s gravity is known, one can caculate roughly
discharging rate according to electrolyte gravity measured. For example, a full battery’s gravity is 1.28, measured
value is 1.20, and therefore 48% of battery’s capacity has been discharged.
② Use a high-rate discharger to measure voltage of single-frame.
High-rate discharger is also called discharge tongs that is composed of one 3V DC voltmeter and one load
resistor, as indicated in Figure 11-1.
Figure 11-1 High-rate Discharger
During measurement, Press firmly tong tips on (+,―)posts of measured cell for 5 seconds, read battery end
voltage value under heavy load discharging process. This will help to decide correctly the discharging rate and
starting capacity.
There are different dischargers supplied by different manufacturers, one should measure and read
current/voltage values according to discharger manual. A good battery’s single cell voltage should be over 5V, and
the value keeps stable during 5 seconds. If in a certain cell, voltage drops quickly in 5 seconds or its read is over
0.1V lower than that of other celles, this cell is failure and should be repaired.
(16)
When to formulate electrolyte, why can only pour sulphate acid into water, not the
other way round?
Blending sulphate acid with water will creat great amount of heat. Water’s specific heat is quite different
from that of sulphate acid, it is 1C/g/℃while concentrate sulphate acid specific heat is 0.33C/g/℃. Pouring water
into concentrate sulphate acid will produce drastic sectional heating and even explosive splashes. But this will not
happen when one pours acid into water because water has higher specific heat. This way is much safer.
(17) How to use and maintain a battery in the winter?
In order to keep battary in good condition to prolong its service life, follwing rules should be observed:
①Always keep battery full to aviod freezing due to low electrolyte gravity. Ice would make case broken,
plate warped and sheddings.
Table 11-7 Discharging / Specific Gravity /
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Chapter 11 Structure, Application and Service of Electrical Devices & Instrument
·243·
Temperature at Freezing Point of Battery
Discharging
Degree
Fully Charged
25%
50%
75%
100%
S.G.
15℃
Freezing
Point
0℃
S.G
15℃
Freezing
Point
0℃
S.G.
15℃
Freezing
Point
0℃
S.G.
15℃
Freezing
Point
0℃
S.G.
15℃
Freezing
Point
0℃
1.310
-76
1.270
-58
1.230
-36
1.190
-22
1.150
-14
1.290
-70
1.250
-50
1.210
-28
1.170
-18
1.13.0
-10
S.G and
Freezing
Point of
Electrolyte
1.280
-69
1.240
-42
1.200
-25
1.160
-16
1.12.
-9
1.270
-58
1.230
-36
1.190
-22
1.150
-14
1.110
-8
1.250
-50
1.210
-28
1.170
-18
1.130
-10
1.09
-6
1.240
-42
1.20
-25
1.160
-16
1.120
-9
1.08
-5
② In winter, it is suggested to add electrolyte with gravity of 1.40 as per chart 11-3 for adjustment..
③ In winter, adding distilled water only at the moment when engine is running (engine is recharging battery)
to avoid icing due to uneven mixing water with electrolyte.
④ In winter a battery’s capacity decreases. Cranking a cold engine at this time should give it enough time to
preheat. When it is hard to start the engine, do not activate starter more than 15 seconds each time, and there
should be 2-3 minutes interval between two consecutive crankings. If engine still cannot startup after three
attempts, one should turn to check engine for fault before next try.
(18)
Why are there yellow or white pastes on battery cover? How to get rid of it?
Pastes on battery cover and around terminals are the results that sulphrate splashes corrode posts, cable
clamp and bracket. White paste is mainly of lead sulphrate, and yellow one is of iron sulphrate. These two types of
pastes have very high electrical resistance, they forms very high contact resistance if they are present at
connectors. To get rid of them, one can use rag soaked with 10% soda solution to clean electrolyte splashes on
battery cover and case, then clean with water and dry them up with clean cloth. Also clean battery terminals and
cables with soda solution. If there are low conductive oxidants, one can use knife to scrape them away. It is better
to apply vasiline or grease on fastened terminals and cable clamps.
(19)
How to cure iced battery?
Frozen battery are mainly caused by:
① Factory battery has very low electrolyte gravity, it freezes when it is used in cold climate;
② Battery has not been recharged timely after being used. Its electrolyte gravity becomes low;
③ Distilled water added has not mixed evenly with electrolyte. Upper and lower part of fluid in battery has
different gravity. (Start up and run engine for some time can help to mix them evenly).
Remove a frozen battery to warm room to let it melt slowly, recharge it slowly with low current. One should
keep watching each cell’s voltage and electrolyte temperature. Electrolyte gravity in a charged battery should
reach rated value. Otherwise one should use distlled water or sulphrate (gravity: 1.400) to make adjustment.
Replace new plate to fix a seriously frozen battery.
Battery typical defect analysis and liabilities
Table 11-8 △ Liabilities of battery supplier ● Liabilities of vehicle user and dealer
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OPERATION AND MAINTENANCE MANUAL FOR FOTON VIEW SERIES LIGHT BUS
·244·
Defect
Defect Analysis
Symptoms
Defect Treatment Liability
Insufficient
Charging
1. Vehicle voltage regulator’s
setting is low
2. Vehicle power consumption is
higher than charged capacity
3. Frequent
start-up,
short
driving distance
4. Alternator failure or circuit
faults
5. Terminals or cable corrosion
1. Voltage
is
around
12V
1. Electrolyte gravity is
lower than 1.220
2. Hard to start-up
3. To
check
with
capacity
analyzer
(yellow or red area)
1.Adjust
regulator
2. Recharge
battery
3. Customer
replaces new
battery
●
Overchargeing
1.Vehicle
voltage
regulator’s
setting is higher
2. Prolonged charging
3. Prolonged and longer distance
driving
4. Higher recharge voltage
1. Battery sump or vent
plug turn black or yellow
2.
Separator
plate
carbonated
3.Positive
post
is
corroded, broken, floated
4.Wet
acid
on
sump
surface
5.Electrolyte level always
lowers or fluid turns
muddy
6.Plate
shedding
falls
evenly
1. Adjust charger
2. Customre
replaces new
battery
●
Over Discharging
1. Use short-charged battery
2. Electrical device short circuit
3. Electrical device is kept on
1. Voltage is below 10V
2. Specific gravity of
electrolyte is below 1.100
3. Low specific gravity
after supplementary
charging
1. Adjust charger
2. Supplementary
charging
3. Customre
replace a new
battery
●
Short Circuit
1. Weld lead enters when a
battery is assembled.
2. Plate is warped to short circuit
3. Separator is missed or broken
during assembling
1. Voltage is around 10V
2. First frame gravity is
the lowest among the six.
3. Tested voltage drops to
lower than 8V, with
“boiling” symptom in
faulty frame.
3. After supplementary
charging, faulty frame’s
gravity is still lower
with less gas generation
Manufacturer
replaces new
battery for
customer
△
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Chapter 11 Structure, Application and Service of Electrical Devices & Instrument
·245·
Defect
Defect Analysis
Symptoms
Defect Treatment Liability
4. Brown or white shedding,
higher charging current;
over-charging; over discharging;
impure electrolyte
4. Large self discharging Customer
replaces new
battery
●
Open Circuit
1.
Poor
welding
at
battery
assembling — terminals and plates
2. Outside short circuit
3. High current discharging
1.Voltage’s
extremely
unstable
2.Terminal melted
3.Voltage is less than 0V
at
discharging,
faulty
frame cell smokes
4.Unable to input current
at
recharging,
battery
smokes or its fluid level
goes up
Customer
replaces new
battery or
manufacturer
repairs
△
●
Incorrect fluid
adding
1. Too high or too low specific
gravity at initial fluid filling
2. Fluid level drops, or wrong fluid
adding (impure water)
While gravity is higher:
1. Gravity after adding≥
300
While gravity is lower
after
separator
is
carbonated:
2. Gravity after adding ≤
1.200
3..Separator plate color is
light
4.Lower battery capacity,
fluid is muddy or with
abnormal color due to
impure fluid
Change
electrolyte,
customer replaces
new battery if it
is seriously
failure.
●
Plate Sulphation
1. Insufficient initial charge
2.
Longer shelf-storing time
3. Under charged for long
4. High specific gravity of
electrolyte
5. Fluid level drops, upper plate is
exposed to air
6. Impure electrolyte
1.Capacity reduced during
normal
dischaging
process
2.Gravity is lower than
normal value
3.Voltage drops quickly at
discharing
4.Bubble production at
charing
5. PbS04 coarse crystals
1.Use
over-charging
method
2.Charging
repeatedly
3.Water treatment
method
4.Customer
replaces
new
battery
●
Excessive
Shedding
1. Brown sediment due to too large
charging current
2. White sediment due to over-
discharging
1. Sediments are found in
fluid, brown
materials
goes up from bottom
2. Battery capacity
1. For plastic case
battery,
repalce
plates
and
remove
●
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OPERATION AND MAINTENANCE MANUAL FOR FOTON VIEW SERIES LIGHT BUS
·246·
Defect
Defect Analysis
Symptoms
Defect Treatment Liability
3. Impurities presence inside
battery
4. Paste shedding due to prolonged
higher gravity and temperature
5. Larger shedding due to poor
plate quality
reduced
sediments
2.Charge
with
low
current,
adjust
fluid
concentration
and
level
at
later stage
3.
Customer
replace
new
battery
4.Mmanufacturer
replaces
new
battery
to
customer
1. Battery separator is perforated
during manufacturing
2. Poor thermal sealing
1. Lower voltage
2.Fluid gravities among
crossed
frames
are
similar, separator is light
in color
3.Fluid
among
frames
flow to each other when
battery is turned down
Manufacturer
replaces new
battery to
customer
△
Cross-frame
electrolyte
leakage
3. Impact of outside force
4. Test cross-flowing fluid
(with analyzer) will creat
gassing, fluid is muddy
Customer replace
a new battery
●
Reversed Polarity
during assembly
1. Reversed polarity during
assembly
2. Reversed polarity during battery
cover mounting
1. 8V for one reversed
frame, and 4V for two
reversed frames
2. 12V for reversed cover
Manufacturer
replaces new
battery to
customer
△
Polarity reversal
at charging
Wrong connection of positve and
negative terminals during charging
1. Negative voltage value
2. Electrolyte specific
gravity is lower than
1.200
3. Colors of +/- plates
are reversed
Customer
reversed charging
or manufacutuer
replace new
battery for
costomer.
△
1.Poor battery cover thermal
sealing.
2. Poor connection between
terminals and cover
1. Leakage—filler hole
2. Leakage at case and
cover junction
3.Tilt battery over 60,
fluid flows out
Manufacturer
replaces new
battery to
customer
△
Fluid Leak
3. Fluid leak dut to impact
4. Impact damage on case Customer replace
a new battery
●
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Chapter 11 Structure, Application and Service of Electrical Devices & Instrument
·247·
Defect
Defect Analysis
Symptoms
Defect Treatment Liability
1. Bad welding or in short circuit
1. Check welding quality
or short circuit
Manufacturer to
make a
replacement
△
2.Vent plug is restricted
2. Vent plug failure due to
obstruction
●
3. Bad contact in terminal
3. Terminal is melted and
damaged
●
4. Spark presence during charging
or operating
4. Case broken, crack
goes from up all the way
down
Manufacturer
assists to repair
or customer
replaces new
battery
●
5. External terminal is in short
circuit
Abrupt cracking
of Battery
6. Circuit failure
5. Check terminals for
possible poor contact
Customer
replaces new
battery
●
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