Hitachi UC 18YFL Manual

TECHNICAL DATA
AND
SERVICE MANUAL
CHARGER
UC 18YRL/UC 18YFL
SPECIFICATIONS AND PARTS ARE SUBJECT TO CHANGE FOR IMPROVEMENT
LIST Nos.: UC 18YRL: G845
UC 18YFL: G844
Nov. 2006
U
MODELS
UC 18YRL
UC 18YFL
Hitachi 
Power Tools

Page
CONTENTS
1. PRODUCT NAME .........................................................................................................................1
2. MARKETING OBJECTIVE ...........................................................................................................1
3. APPLICATIONS ............................................................................................................................1
4. SELLING POINTS ........................................................................................................................2
4-1. Selling Point Descriptions ............................................................................................................ 3
5. SPECIFICATIONS ........................................................................................................................7
5-1. Specifications ............................................................................................................................... 7
5-2. Comparisons with Similar Products ............................................................................................. 7
6. PRECAUTIONS IN SALES PROMOTION ...................................................................................8
6-1. Safety Instructions ....................................................................................................................... 8
6-2. Extra Precautions in Sales Promotion ......................................................................................... 9
7. QUESTIONS AND ANSWERS ON MODELS UC 18YRL AND UC 18YFL ...............................10
8. GENERAL PRECAUTIONS .......................................................................................................13
8-1. Models UC 18YRL and UC 18YFL ............................................................................................ 13
8-2. Pilot Lamp Indications ................................................................................................................ 13
9. PRECAUTIONS IN DISASSEMBLY AND REASSEMBLY ........................................................14
9-1. Disassembly ............................................................................................................................. 14
9-2. Reassembly ............................................................................................................................... 14
9-3. Confirmation after Reassembly ................................................................................................. 14
10. TROUBLESHOOTING GUIDE .................................................................................................15
10-1. Troubleshooting Based on Pilot Lamp Indications ................................................................... 15
10-2. Troubleshooting and Repair Procedures ................................................................................. 15
11. STANDARD REPAIR TIME (UNIT) SCHEDULES.................................................................... 19
Assembly Diagram for UC 18YRL
Assembly Diagram for UC 18YFL

1
1. PRODUCT NAME
Hitachi Charger, Models UC 18YRL and UC 18YFL
2. MARKETING OBJECTIVE
The new chargers Models UC 18YRL and UC 18YFL are developed to recharge the Hitachi's new lithium-ion
batteries. They are also capable of recharging the currently applicable nickel cadmium (Ni-Cd) and nickel metal
hydride (Ni-MH) batteries. Thanks to the cooling fan incorporated in the Model UC 18YRL (except the Model
UC 18YFL), the time required for recharging a battery and the time required for waiting until a hot battery is cooled
down to the allowable temperature are substantially shorter than the Model UC 24YFA.
3. APPLICATIONS
Recharging of Hitachi batteries
Applicable batteries:
EB 712S [7.2 V, 1.2 Ah]
EB 912S [9.6 V, 1.2 Ah]
EB 1212S [12 V, 1.2 Ah]
EB 1412S [14.4 V, 1.2 Ah]
EB 7S [7.2 V, 1.3 Ah]
EB 9S [9.6 V, 1.3 Ah]
EB 12S [12 V, 1.3 Ah]
EB 914 [9.6 V, 1.4 Ah]
EB 1414 [14.4 V, 1.4 Ah]
EB 9B [9.6 V, 2.0 Ah]
EB 12B [12 V, 2.0 Ah]
EB 14B [14.4 V, 2.0 Ah]
EB 1220BL [12 V, 2.0 Ah]
EB 924 [9.6 V, 2.4 Ah]
EB 1224 [12 V, 2.4 Ah]
EB 1424 [14.4 V, 2.4 Ah]
Ni-Cd batteries*
Ni-MH batteries EB 1222HL [12 V, 2.2 Ah]
EB 930H [9.6 V, 3.0 Ah]
EB 1230H [12 V, 3.0 Ah]
EB 1230HL [12 V, 3.0 Ah]
EB 1430H [14.4 V, 3.0 Ah]
EB 926H [9.6 V, 2.6 Ah]
EB 1226H [12 V, 2.6 Ah]
EB 1426H [14.4 V, 2.6 Ah]
EB 1826HL
Super Ni-MH batteries EB 933X [9.6 V, 3.3 Ah]
EB 1230X [12 V, 3.0 Ah]
EB 1233X [12 V, 3.3 Ah]
EB 1430X [14.4 V, 3.0 Ah]
EB 1433X [14.4 V, 3.3 Ah]
EB 1830X [18 V, 3.0 Ah]
EB 1833X [18 V, 3.3 Ah]
Li-ion batteries EBL 1430 [14.4 V, 3.0 Ah]
EBM 1830 [18 V, 3.0 Ah]
EB 714S [7.2 V, 1.4 Ah]
FEB 7S [7.2 V, 1.2 Ah]
EB 7B [7.2 V, 2.0 Ah]
EB 914S [9.6 V, 1.4 Ah]
FEB 9S [9.6 V, 1.2 Ah]
FEB 12S [12 V, 1.4 Ah]
EB 1214S [12 V, 1.4 Ah]
EB 1214L [12 V, 1.4 Ah]
EB 1414S [14.4 V, 1.4 Ah]
EB 1812S [18 V, 1.2 Ah]
EB 18B [18 V, 2.0 Ah]
EB 1820 [18 V, 2.0 Ah]
EB 1814SL [18 V, 1.4 Ah]
EB 1820L [18 V, 2.0 Ah]
EB 1824L [18 V, 2.4 Ah]

2
EB 712S
EB 7S
EB714S
FEB7S
EB7B
EB 912S
EB 9S
EB 914S
EB 914
FEB 9S
EB 9B
EB 924
EB 926H
EB 930H
EB 933X
EB 12S
FEB 12S
EB 12B
EB 1226H
EB 1230H
EB 1412S
EB 1414S
EB 1414
EB 14B
EB 1424
EB 1426H
EB 1430H
EB 1430X
EB 1433X
EB 1212S
EB 1214S
EB 1214L
EB 1220BL
EB 1224
EB 1230HL
EB 1230X
EB 1233X
General purpose charger capable of
recharging 7.2 V to 18 V batteries
4. SELLING POINTS
(1) Accepts both Ni-MH and Ni-Cd batteries
(2) Rapidly charges all Hitachi EB-series batteries
Charging time:
1.2 Ah •••••• 18 minutes 2.0 Ah •••••• 30 minutes 2.6 Ah •••••• 40 minutes 3.3 Ah •••••• 50 minutes
1.4 Ah •••••• 20 minutes 2.4 Ah •••••• 35 minutes 3.0 Ah •••••• 45 minutes
(3) Hitachi original charge control mechanism for longer battery life
Easy-to-read visual display of charging
status through constant lighting or flashing
of red and green pilot lamps
Fig. 1
3-way overcharging
protection systems
for longer battery
and charger life
Capable of recharging both nickel cadmium (Ni-Cd), nickel metal hydride (Ni-MH),
SUPER nickel metal hydride (SUPER Ni-MH) and Lithium ion (Li-ion) batteries
Recharging/discharging cycles of battery
(ambient temperature range between 10ûC and 30ûC)
• Ni-Cd: about 1,000 times • SUPER Ni-MH: about 1,500 times
• Ni-MH: about 500 times • Li-ion: about 1,500 times
Capable of recharging batteries with internal temperatures
as high as 60ûC (nickel cadmium (Ni-Cd) batteries)
EBL 1430
EB 1812S
EB 18B
EB 1820
EB 1830H
EB 1814SL
EB 1820L
EB 1824L
EB 1826HL
EB 1830HL
EB 1830X
EB 1833X
EBM 1830

3
4-1. Selling Point Descriptions
4-1-1. Capable of handling both nickel cadmium (Ni-Cd), nickel metal hydride (Ni-MH), SUPER nickel metal
hydride (SUPER Ni-MH) and litium ion (Li-ion) batteries
Thanks to the application of HITACHI's microcomputer and electronic-circuit control technology, the Model
UC 18YRL/UC 18YFL is capable of handling Ni-Cd, Ni-MH, SUPER nickel metal hydride (SUPER Ni-MH) and
lithium-ion (Li-ion) batteries.
4-1-2. Recharging/discharging cycles of battery (ambient temperature range between 10ûC and 30ûC)
• Ni-Cd battery: about 1,000 times • SUPER Ni-NH: about 1,500 times
• Ni-MH battery: about 500 times • Li-ion: about 1,500 times
Recharging/discharging cycles of Ni-Cd, Ni-MH and SUPER Ni-MH batteries can be dramatically increased by
stopping recharging just before the overcharging range by means of the system or the dT/dt system. (Refer
to 4-1-4 for detail.) When recharging a lithium-ion battery, the Model UC 18YRL/UC 18YFL can detect the
decrease in charging current (stop current) and stop recharging automatically.
4-1-3. Capable of recharging batteries with internal temperatures as high as 60 ûC
Each nickel cadmium (Ni-Cd) battery shown in Figs. 2 and 3 incorporates a thermistor. The Models UC 18YRL
and UC 18YFL can continue recharging these batteries until the battery temperature reaches 60 ûC.
(Note 1) • Wiring diagrams for batteries are shown below.
• The thermistor is an element to detect the battery temperature.
• The 95 ûC thermal protector incorporated in each 14.4 V and 18 V battery interrupts the recharging
circuit when the battery temperature reaches 95 ûC.
• The discriminating resistor is incorporated to distinguish Ni-Cd batteries from other batteries.
• Because the nickel metal hydride (Ni-MH), SUPER nickel metal hydride (SUPER Ni-MH) and
lithium-ion (Li-ion) batteries are heated to high temperatures during recharging, this charger
operates within a range of 10ûC temperature difference between the maximum battery temperature
when starting recharging (45 ûC) and the temperature when stopping recharging (55 ûC).
Thermistor
Fig. 2 Ni-Cd batteries (7.2 to 12 V)
Thermostat
terminal
+
terminal
S
terminal
--
Thermistor
95 ûC thermal protector
terminal
--
terminal
+
terminal
--
terminal
S
(Terminal positions)(Terminal positions)
Fig. 3 Ni-Cd batteries (14.4 V, 18 V)
terminal
T

4
(Terminal positions)
(Terminal positions)
Fig. 4 • Ni-MH batteries (9.6 to 12 V)
• SUPER Ni-MH batteries (9.6 to 12 V)
terminal
T
Fig. 5 • Ni-MH batteries (14.4 V, 18 V)
• SUPER Ni-MH batteries (14.4 V, 18 V)
terminal
+
terminal
S
terminal
--
Thermistor
Discriminating
resistor
terminal
--
terminal
+
terminal
S
terminal
--
terminal
T
95 ûC thermal protector
Thermistor
Discriminating
resistor
Fig. 6 Li-ion batteries (14.4 V, 18 V)
(Terminal positions)
terminal
T
terminal
--
terminal
LS
Discriminating
resistor
Thermistor
95ûC thermal protector
Protective
circuit board
terminal
+
L+
terminal
LE
terminal

5
Battery voltage
Charger output current Charger output voltage Battery internal gas pressure Battery temperature Battery voltage
Overcharge range
Battery temperature 60 C
120-minute timer
Ni-Cd battery temperature
Charging time
Battery internal
gas pressure
Battery temperature 55 C
dT/dt
Ni-MH battery
temperature
V
Stop current 2A
Li-ion battery
Charger output current
Li-ion battery
Charger output voltage
4-1-4. 3-way overcharge protection system
Overcharge protection is ensured by a (A) 2V system or dT/dt system (for Ni-MH battery), (B) built-in battery
temperature sensor (thermistor) and (C) a timer.
Fig. 7 Relationships of time, voltage, temperature and gas pressure while charging
(A) • : This detects the fall in battery voltage at the end of charging using the value and suspends
charging.
dT/dt : This system is applicable to Ni-MH and SUPER Ni-MH batteries. This detects the variation in
temperature of Ni-MH and SUPER Ni-MH batteries by the value dT/dt at the end of charging and suspends
charging.
(B) • Built-in battery temperature sensor : In the event both the system and the dT/dt system fail to detect
completion of recharging, recharging is automatically stopped when the battery temperature reaches 60ûC in
the case of the nickel cadmium (Ni-Cd) batteries or 55ûC in the case of the nickel metal hydride (Ni-MH),
SUPER nickel metal hydride (SUPER Ni-MH) and lithium-ion (Li-ion) batteries.
(C) • Timer : Should both the system, dT/dt system and the temperature sensor fail, the timer automatically
stops charging within 120 minutes from the beginning of charging.
(Note 2) The voltage of the battery increases during charging and begins to fall when further charging is not
possible. The system detects the point where the voltage begins to fall, and suspends charging
to protect the battery from overcharging.
(Note 3) The temperature rise during charging of a Ni-MH or SUPER Ni-MH battery is higher than a Ni-Cd
battery, and a sudden temperature rise occurs just before the battery is fully charged. The dT/dt
system detects the point where the temperature rises suddenly and suspends charging to minimize
the temperature rise.
(Note 4) As shown in Fig. 7, the pressure of gas generated after a battery has become fully charged rises
rapidly to cause high temperature and high gas pressure that degrade the effectiveness of the
battery. If charging is allowed to continue, the pressure of the gas will activate the safety valve in the
battery, and the electrolyte will begin leaking.

6
4-1-5. Easy-to-read visual display of charging status through constant lighting or flashing of red and green pilot
lamps
Rechargeable batteries Rechargeable battery temperature range
EB712S, EB7S, EB714S, FEB7S, EB7B, EB912S,
EB9S, EB914S, EB914, FEB9S, EB9B, EB924,
EB1212S, EB12S, EB1214S, EB1214L, FEB12S,
EB12B, EB1220BL, EB1224, EB1412S, EB1414S,
EB1414, EB14B, EB1424, EB1812S, EB1814SL,
EB18B, EB1820, EB1820L, EB1824L
23ûF to 131ûF (-5ûC to 55ûC)
NOTE: The Model UC 18YRL cools the overheated battery by the cooling fan during the standby
mode.
Rechargeable battery temperature range
The rechargeable battery temperature ranges are shown in the table below. Overheated batteries should be
cooled to the specified temperature before recharging.
EB926H, EB930H, EB933X, EB1226H,
EB1230H, EB1230HL, EB1230X, EB1233X,
EB1426H, EB1430H, EB1430X, EB1433X,
EB1826HL, EB1830H, EB1830HL, EB1830X, EB1833X
EBL1430, EBM1830
23ûF to 122ûF (-5ûC to 50ûC)
32ûF to 122ûF (0ûC to 50ûC)
Pilot lamp indication
Charge
status
lamp (Red)
Overheat
lamp
(Green)
Before
charging
During
charging
Overheat
standby
Charging
impossible
Charging
completed
Blinks
(Red)
Lights
(Red)
Flickers
(Red)
Blinks
(Red)
Lights
(Green)
0.5 sec. ON 0.5 sec. OFF
Stays ON continuously
Stays ON continuously
Battery or charger is faulty.
Battery is overheated.
Unable to charge.
(Charging will commence
when the battery is cooled.)
0.5 sec. ON 0.5 sec. OFF
0.1 sec. ON 0.1 sec. OFF

7
5. SPECIFICATIONS
5-1. Specifications
Descriptions
Item
AC single-phase, 50 Hz or 60 Hz
95 W
Constant current charge with feedback control
Constant current and voltage control (Li-ion batteries)
(1) Battery voltage detection ( system)
Battery temperature detection (dT/dt system) for Ni-MH and SUPER
Ni-MH batteries
(2) Battery surface temperature detection (thermistor)
(3) 120-minute timer
(4) Stop current detection (Li-ion batteries)
7.2 V to 18 V
0.6 kg
0 ûC to 40 ûC
Power source
Charging system
Overcharging protection system
Charging voltage
Charging current
Charging time
Product weight
Operating ambient temperature range
5-2. Comparisons with Similar Products
Power input
3.3 A
Approx. 45 minutes (for 3.0 Ah)
(*1): Chargeable Ni-Cd battery temperature range
(*2): Chargeable Ni-MH/SUPER Ni-MH battery temperature range
(*3): Chargeable Li-ion battery temperature range
HITACHI
UC 18YRL •UC 18YFL
Charging time
Overcharge protection
system
Charging voltage
min. 45
(3.0 Ah)
V7.2 to 18
Charging current A 3.3
Power input W 95
Operating ambient
temperature range ûC0 to 40
Chargeable battery
temperature range ûC(*1) - 5 to 55 (*2) - 5 to 50
(*3) 0 to 50
---
system, dT/dt system, battery
surface temperature detection, timer,
stop current detection
External dimensions
(length x width x height)
mm 226 x 110 x 75
Weight kg 0.6 (1.3 lbs.)
70
(3.0 Ah)
7.2 to 24
2.5
90
2V system, battery surface, dT/dt
system temperature detection, timer
226 x 110 x 75
0.6 (1.3 lbs.)
0 to 40
(*1) - 5 to 60
(*2) 0 to 45
UC 24YFA

8
6. PRECAUTIONS IN SALES PROMOTION
6-1. Safety Instructions
In the interest of promoting the safest and most efficient use of the Model UC 18YRL and UC 18YFL Chargers by
all of our customers, it is very important that at the time of sale the salesperson carefully ensures that the buyer
seriously recognizes the importance of the contents of the Handling Instructions.
6-1-1. Handling instructions
Salespersons must be thoroughly familiar with the contents of the Handling Instructions in order to give pertinent
advice to the customer.
(1) Connect the charger to an AC power outlet only.
Use of any other power source (DC outlet, fuel-powered generator, etc.) will cause the charger to overheat
and burn out.
(2) Do not use any voltage-increasing equipment (transformer, voltage regulator, etc.) between the power source
and the charger.
If the charger is used with voltage over and above that indicated on the unit, it will not function properly.
(3) Conduct battery charging in an ambient temperature range of 0ûC to 40ûC.
If charging is attempted when the ambient temperature is below 0ûC, charging is not possible or overcharging
occurs because the recharging control circuit does not function properly. If charging is attempted when the
ambient temperature is above 40ûC, charging is stopped before the battery is fully charged due to temperature
rise during charging because the difference between the upper limit of the rechargeable battery temperature
(Ni-Cd batteries: 60ûC, Ni-MH batteries: 55ûC, SUPER Ni-MH batteries: 50ûC, Li-ion batteries: 55ûC) and the
ambient temperature is small.
(4) Do not use the charger for successive charging.
In very hot locations, if two or more batteries are charged successively, the temperature of the charger will rise
excessively and might cause the charger to fail. Instruct the customer to wait at least 5 minutes before
commencing next charging. Particular care is necessary in summer or tropical countries when the power
source voltage is low.
(5) Do not insert foreign objects into the air vent on the charger.
The charger case is equipped with air vents to protect the internal electronic components from overheating.
Caution the customer not to allow foreign materials, such as metallic or inflammable objects, to be dropped or
inserted into the air vents. This could cause electrical shock, fire or other serious hazards.
(6) Do not attempt to disassemble the charger.
Incorrect parts replacement and/or wiring will cause malfunctions which could result in fire or other hazards.
Instruct the customer to bring the charger to an authorized service center in the event repair or replacement is
necessary.