2021 HYUNDAI NEXO battery

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OFEQ018001N/OFEQ018002/OFEQ018003/OFEQ018004/OFEQ018005
(1) Fuel Cell system
(2) Traction motor system(3) Hydrogen Tanks
(4) Battery System
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1. Fuel cell stack
A fuel cell stack is a device that con-
verts the chemical energy into elec-
tricity thorough a chemical reaction
with hydrogen and oxygen. Fuel cell
is different from battery in that it
requires hydrogen and oxygen con-
stantly in order to operate. And it can
produce electricity continually for as
long as hydrogen and oxygen are
supplied. A fuel cell stack is com-
posed of many unit cells to obtain the
desired power for a vehicle.
2. FCEV powertrain
1. High voltage junction box
2. Fuel cell stack
3. Traction motor4. Reduction gear
5. Air compressor
The main components of FCEV are
Fuel cell stack, air processing sys-
tem, fuel processing system, thermal
management system, hydrogen stor-
age tanks, high voltage battery, DC-
DC converter, inverter and traction
motor, gear differential unit.
The Air compressor supplies air to fuel
cell system and the hydrogen storage
tanks supplies hydrogen fuel to fuel
cell system. Then the electric energy
comes from the fuel cell system.
The electric energy deliveried to the
motor inverter. The energy finally
moves to motor operating.
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OFEQ018006NOFEQ018007N
OFEQ018008
If you assemble or disassemble
the stack and fuel cell system,
hydrogen may leak resulting in
fire and this may lead to acci-
dents. Never assemble or disas-
semble the stack and fuel cell
system.
WARNING

H5
3. High pressure hydrogen
storage tanks
Compressed hydrogen tank system
is composed of three tanks which
are filled with hydrogen gas in a gas
station. Each tank is made of plastic
liner for blocking the hydrogen per-
meation and carbon fiber layer sus-
tain high pressures.
There are main parts to supply
hydrogen stably and to enable safety
such as magnetic valves, pressure
regulator, pressure sensors, pres-
sure relief valve, excess flow valve
and so on. The hydrogen in the tanks
comes into the pressure regulator
which has a pressure sensor.
4. Battery system
A 12 V battery integrated with the low
and high voltage batteries is installed
in the vehicle. The battery supplies
the electricity required for driving the
vehicle and stores the energy gener-
ated from the regenerative braking.
When the vehicle accelerates the
auxiliary power of the fuel cell sup-
plies the energy. The vehicle can
drive about 2 miles (3 km) in EV
mode until the high voltage battery is
discharged.
High voltage cables
The electric energy which is generat-
ed from fuel cell system or high volt-
age battery module is distributed to
the various components. Most of the
cables are located in the inside or bot-
tom of the components. These cables
use orange colored cover to distin-
guish from other lines. It is required to
handle the cables carefully with isola-
tion gloves.
OFEQ018004
OFEQ018005

H6
Disconnecting negative (-)
battery cable
1. Fold up the luggage board of the
liftgate.
2. Disconnect the negative (-) con-
nector.
Hydrogen gas detection
sensors
They detect a hydrogen leak and
informs a warning of hydrogen leak
to a driver. As informing a warning,
the sensors automatically shut off
hydrogen. Sensors are installed
around the hydrogen storage tanks
and FCEV system module.
These sensors prevent a hydrogen
leak in an emergency. Even if the
hydrogen leak occurs, the Fuel cell
electric operating does not active.
The system operating is changed to
EV (Electric vehicle) mode and you
may drive the vehicle about 2 miles
(3 km). However, we recommend
that you stop the vehicle to the safe-
ty place and contact an authorized
HYUNDAI dealer.
OFEQ018009
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Never touch orange or high
voltage labeled components
including wires, cables, and
connections.
If the insulators or covers are
damaged or removed, severe
injury or death from electrocu-
tion may occur.
WARNING
In the fuel cell system, the bat-
tery uses high voltage to oper-
ate the motor and other compo-
nents.
This high voltage battery sys-
tem can be very dangerous.
Never touch the system. If you
touch the battery system, seri-
ous injury or death may occur.
WARNING

H7
OFEQ018010
•Do not disassemble or assem-
ble the high voltage battery
system. Doing so may result
in electric shock causing
death or serious injury.
If you disassemble or assem-
ble system components
improperly, it may damage the
performance and reliability of
your vehicle.
If coolant and electrolyte
come in contact with your
body, clothes or eyes, immedi-
ately flush with a large quanti-
ty of fresh tap water. Have
your eyes examined by a doc-
tor as soon as possible.
WARNING
Never assemble or disassemble
the high voltage battery system.
If you assemble or disassem-
ble the high voltage battery
system, the durability and
performance of the vehicle
may be damaged.
When you want to check the
high voltage battery system,
contact an authorized
HYUNDAI dealer.
Do not touch the high voltage
battery and high voltage cable
connected to motor (orange
color). Severe burns and elec-
tric shock may occur. For your
safety, do not touch the cover
of electronic components and
electronic cable. Do not
remove the cover of electron-
ic components and electronic
cable. In particular, never
touch the high voltage battery
system when the FCEV sys-
tem is operating. It may result
in death or serious injury.
WARNING
Never use the package mod-
ules (high voltage battery,
inverter, converter) for any
other purpose.
Do not use an after-market
battery charger to charge the
high voltage battery. Doing so
may result in death or serious
injury.
Never get near or put a high
voltage battery system in a
fire. Doing so may result in
serious burns.
Never drill into, strike or oth-
erwise damage the package
modules. An electric shock
may occur resulting in seri-
ous injury or death.
WARNING

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This vehicle uses the high volt-
age battery system to generate
high voltage.
High voltage in the battery sys-
tem is very dangerous and can
cause severe burns and electric
shock. This may result in seri-
ous injury or death.
For your safety, never touch,
replace, dismantle or remove
the high voltage battery sys-
tem including components,
cables and connectors.
Severe burns or electric
shock may result in serious
injury or death if you do not
follow this warning.
When the high voltage battery
system operates, the battery
system can be hot. Always be
careful because burns or elec-
tric shock may be caused by
high voltage.
Do not drop water or liquid on
to Fuel cell power module
compartment. The system
components are covered. If
you drop water or liquid on to
system components, it may
result in electric shock.
WARNING
When the vehicle is paint
baked, do not pass 30 min-
utes in 158°F (70°C) or 20 min-
utes in 176°F (80°C) degree.
When you clean the fuel cell
power module compartment,
do not wash using water.
Water may cause an electric
shock to occur and damage
electronic parts and compo-
nents.
CAUTION
Do not assemble or disassem-
ble the hydrogen tanks.
Improper work may damage
the performance and reliabili-
ty and unexpected problem
may occur. For hydrogen
tanks work, contact an author-
ized HYUNDAI dealer.
Never drill into, strike or oth-
erwise damage the hydrogen
tanks. Unexpected problem
may occur resulting in seri-
ous injury and death.
Never get near or put a hydro-
gen tanks in a fire. Doing so
may result in big injury.
Never use the hydrogen tank
for any other purpose.
WARNING

H9
Service plug
OFEQ018011
The FCEV system contains
many electronic components.
High voltage components like
cables and other parts may emit
electromagnetic waves. Even if
the electromagnetic cover
blocks electromagnetic emis-
sions, electromagnetic waves
may have an effect on electron-
ic appliances. If you park the
vehicle for a long time, the high
voltage battery or 12V battery
will discharge. You need to drive
the vehicle several times per
month. We recommend driving
at least 10 minutes or 2 miles (3
km) when you drive the vehicle.
If the high voltage battery is dis-
charged and if it is impossible
to jump start the vehicle contact
your HYUNDAI dealer.
CAUTION
When you start the FCEV sys-
tem in the "P" or "N" gear
position, the "Ready ( )"
indicator is illuminated in the
cluster. The driver can drive
the vehicle.
When you leave the vehicle,
you should turn off the sys-
tem or shift into the "P" posi-
tion. If you depress the accel-
erator pedal by mistake and
the vehicle is not in the "P"
position, the vehicle will move
abruptly. This may result in
serious injury or death.
WARNING
Never touch the service plug
under the rear seat.
The service plug is attached to
the high voltage battery system.
Touching the service plug will
result in death or serious injury.
Service personnel should fol-
low procedures in service man-
ual.
WARNING

H17
Close fuel door before turning
vehicle On
This warning message is displayed
when you turn on the vehicle with
the fuel filler door open. Close the
fuel filler door and turn on the vehicle
again.
Hydrogen tank overfilled due
to hydrogen station error
This warning message is displayed
when the hydrogen tank is over-refu-
eled with the hydrogen due to a prob-
lem of the fueling station.
Turn off the vehicle and then turn on
the vehicle. If the message is dis-
played again, have the vehicle
checked by an authorized HYUNDAI
dealer.Small hydrogen leak possible
This warning message is displayed
when the minor hydrogen leakage is
detected in the vehicle. In this case,
have the vehicle checked by an
authorized HYUNDAI dealer.
If the vehicle has to be stopped due
to the leakage, hydrogen gas leak
warning light (red) will illuminate and
'Hydrogen leak detected. Stop safely
immediately.' message is displayed.
Power limited due to low
hydrogen tank temperature
This warning message is displayed
to protect the battery and fuel cell
system when the temperature of the
hydrogen tanks is low.
If this message is still displayed after
the ambient temperature has
increased enough, have the vehicle
checked by an authorized HYUNDAI
dealer.Hydrogen tank temperature
out of range! Stop safely
immediately
This warning message is displayed
to protect the hydrogen tank system
when the temperature of the hydro-
gen tank is too high or too low.
Turn off the vehicle and stop to let
the temperature of the hydrogen tank
go down.▲ ▲
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If this message is still displayed
after the vehicle is turned off
and stopped for a sufficient
time, we recommend you to
stop driving and have your vehi-
cle immediately inspected by an
authorized HYUNDAI dealer.
WARNING