2023 HYUNDAI NEXO battery reset

6-5
What to do in an emergency
6
Before Jump Starting
This vehicle does not have a regular
12V battery that needs periodic
replacement. It is lithium ion polymer
type integrated into the high voltage
battery. The vehicle has a 12V bat-
tery protection system that cuts 12V
battery from vehicle draw to prevent
full discharge.
Using the 12V Battery ResetSwitch
1. Press the 12V Battery Reset switch to reconnect the 12V bat-
tery.
2. Start the vehicle within 15 sec- onds of pressing the 12V Battery
Reset switch.
3. After starting vehicle ( indica- tor on), move the vehicle outside
and keep the vehicle ready ( )
mode more than 30 minutes safe-
ly to charge the 12V battery. If you do not start the vehicle imme-
diately after pressing the 12V Battery
Reset switch, the power of 12V bat-
tery is automatically disconnected
after few seconds to save the 12V
battery from additional discharge. If
the 12V battery is disconnected prior
to starting the vehicle, press the 12V
Battery Reset switch again and then
immediately start the vehicle as
explained.
Repeated use of the 12V Battery
Reset switch without a sufficient
vehicle ON cycle (30 Min+) may
cause over discharge of the 12V bat-
tery, which will prevent the vehicle
from starting. If the 12V battery is
over discharged to a point that the
reset does not work, try to jump-start
the vehicle.
Information
After starting the vehicle ( indica-
tor on), the 12V battery is being
charged whether the accelerator pedal
is depressed or not.
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6-6
What to do in an emergency
The following items may need to be
reset after the battery has been dis-
charged or the battery has been dis-
connected. See chapter 3 or 4 for:
Power Windows
Trip Computer
Climate Control System
Clock
Audio System
Sunroof
Driver Position Memory System
External power source using 12V
battery
The use of external power acces-
sories may reduce performance
and function of the vehicle.
Especially, the use of dash cam-
eras may shut off the power of the
vehicle prior to the dash camera's
automatic shut-down.
If the power of the vehicle is shut
off, start the vehicle as explained.
(refer to "Using the 12V Battery
Switch")Jump Starting
In the event vehicle still does not
have a functional 12V battery (check
if interior lights will not turn on) then
you can try a jump start using a 12V
booster pack or jumper cables from
another vehicle's 12V battery
according to the following instruc-
tions.1. Position the vehicles close enough
that the jumper cables will reach,
but do not allow the vehicles totouch.
2. Avoid fans or any moving parts in the fuel cell power module com-
partment at all times, even when
the vehicles are turned off.
3. Turn off all electrical devices such as radios, lights, air conditioning,
etc. Put the vehicles in P (Park)
and set the parking brake. Turn
both vehicles OFF.
NOTICE
Jump starting can be danger-
ous if done incorrectly. Follow
the jump starting procedure in
this section to avoid serious
injury or damage to your vehi-
cle. If in doubt about how to
properly jump start your vehi-
cle, we strongly recommend
that you have a service techni-
cian or towing service do it for
you.
CAUTION

6-7
What to do in an emergency
64. Connect the jumper cables in theexact sequence shown in the illus-
tration. First connect one jumper
cable to the red, positive (+)
jumper terminal of your vehicle(1).
5. Connect the other end of the jumper cable to the red, positive
(+) battery/jumper terminal of the
assisting vehicle (2). 6. Connect the second jumper cable
to the black, negative (-) battery/
chassis ground of the assisting
vehicle (3).
7. Connect the other end of the sec- ond jumper cable to the black,
negative (-) chassis ground of
your vehicle (4).
Do not allow the jumper cables to
contact anything except the cor-
rect battery or jumper terminals or
the correct ground. Do not lean
over the battery when making
connections. 8. Press the 12V Battery Reset
switch.
9. Start the engine of the assisting vehicle and let it run for a few min-
utes.
10. Start your vehicle as soon as possible. After starting vehicle
( indicator on), operate the
vehicle safely outdoors in ready
mode stopped and/or drive it for
30 minutes total to charge the
12V battery fully.
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7
Maintenance
7
Maintenance
Fuel Cell Power Module Compartment ...............7-3
Maintenance Services ...........................................7-4Owner's Responsibility .....................................................7-4
Owner Maintenance Precautions..................................7-4
Owner Maintenance ..............................................7-5 Owner Maintenance Schedule .......................................7-6
Scheduled Maintenance Services........................7-7 Normal Maintenance Schedule ......................................7-8
Maintenance Under Severe Usage Conditions ........7-10
Explanation of Scheduled Maintenance Items ..7-12
Device Cooling Coolant .......................................7-13 Checking the Coolant Level ..........................................7-13
Changing Coolant ............................................................7-15
Stack Cooling Coolant .........................................7-16 Checking the Coolant Level ..........................................7-16
Changing Coolant ............................................................7-18
Brake Fluid ............................................................7-19 Checking the Brake Fluid Level ...................................7-19
Washer Fluid .........................................................7-20 Checking the Washer Fluid Level................................7-20
Air Cleaner ............................................................7-20 Filter Replacement ..........................................................7-20
Climate Control Air Filter ....................................7-22 Filter Inspection ...............................................................7-22 Wiper Blades.........................................................7-24
Blade Inspection ..............................................................7-24
Blade Replacement .........................................................7-24
12V Battery ...........................................................7-27 Battery Recharging ........................................................7-28
Reset Features.................................................................7-28
Tires and Wheels .................................................7-29 Tire Care ............................................................................7-29
Recommended Cold Tire Inflation Pressures ...........7-30
Check Tire Inflation Pressure ......................................7-31
Tire Rotation.....................................................................7-32
Wheel Alignment and Tire Balance ............................7-33
Tire Replacement ............................................................7-33
Wheel Replacement ........................................................7-34
Tire Traction .....................................................................7-34
Tire Maintenance ............................................................7-34
Tire Sidewall Labeling ....................................................7-34
Tire Terminology and Definitions................................7-38
All Season Tires ...............................................................7-42
Summer Tires ...................................................................7-42
Snow Tires ........................................................................7-42
Radial-Ply Tires ...............................................................7-42
Low Aspect Ratio Tires..................................................7-43
7

7-28
Maintenance
Battery Recharging
By RESET button
To charge the discharged 12V bat-
tery, attempt charging by pressing
12V BATT RESET button. For more
details, refer to “If the 12 volt battery
is discharged” in chapter 6.
By jump starting
After a jump start from a good bat-
tery, drive the vehicle for 20-30 min-
utes before it is shutoff. The vehicle
may not restart if you shut it off
before the battery had a chance to
adequately recharge. See "Jump
Starting" in chapter 6 For more
details on jump starting procedures.
Reset Features
Some items need to be reset after
the battery has been discharged or
the battery has been disconnected.
See chapter 3 or 4 for:
Power Windows
Trip Computer
Climate Control System
Clock
Audio System
Sunroof
Driver Position Memory System
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When the high voltage battery is weak
When the high voltage battery is
weak due to driving on a hill for a
long time or accelerating and decel-
erating the vehicle repeatedly, the
acceleration performance may be
lower than usual. In this case, be
cautious not to overtake other vehi-
cles.
If the 12 volt battery is dis-
charged
This vehicle does not have a regular
12V battery that needs periodic
replacement. It is lithium ion polymer
type integrated into the high voltage
battery. The vehicle has a 12V bat-
tery protection system that cuts 12V
battery from vehicle draw to prevent
full discharge.
If the 12V battery is discharged, you
should try charging it by pressing the
"12V BATT RESET" button.
Using the 12V battery resetswitch
1. Press the 12V Battery Reset switch to reconnect the 12V bat-
tery.
2. Start the vehicle within 15 sec- onds of pressing the 12V Battery
Reset switch.
3. After starting vehicle ( indica- tor on), move the vehicle outside
and keep the vehicle ready ( )
mode more than 30 minutes safe-
ly to charge the 12V battery.
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H26
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If you do not start the vehicle imme-
diately after pressing the 12V Battery
Reset switch, the power of 12V bat-
tery is automatically disconnected
after few seconds to save the 12V
battery from additional discharge. If
the 12V battery is disconnected prior
to starting the vehicle, press the 12V
Battery Reset switch again and then
immediately start the vehicle as
explained.
Repeated use of the 12V Battery
Reset switch without a sufficient ON
cycle (30 Min+) may cause over dis-
charge of the 12V battery, which will
prevent the vehicle from starting. If
the 12V battery is over discharged to
a point that the reset does not work,
try to jump-start the vehicle. Information
After starting the vehicle ( indica-
tor on), the 12V battery is being
charged whether the accelerator pedal
is depressed or not. ❈
❈ For more details regarding the
jump start, refer to the 'Jump star-
ing' in Owner's manual Chapter 6.
Emergency while driving
If an accident occurs
1. Stop the vehicle, put the gear into
the P(Park) position, set the park-
ing brake, and turn the vehicle off
to prevent the hydrogen and cur-rent from leaking.
The flow of hydrogen into the fuel cell stack will be shut off to prevent
the current from being generated.
2. Evacuate to the safety place.
3. Call emergency services for help and let them know the vehicle is a
Fuel Cell Electric Vehicle.
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H33
CategoryQuestionsAnswers
Vehicle
Management (12 items)
11. Can I wash my FCEV with pressurized water? What if water flows into the fuel
cell power module compartment?
Every component housed in the fuel cell power module compart-
ment is designed to be waterproof like those found in standard vehi-
cles. Therefore, a short circuit of the FCEV cannot happen while
washing the car. However, your FCEV works by utilizing high-voltage
electric power, so it is recommended that you avoid high-pressure car
washes. If the insulation resistance of the FCEV deteriorates due to
car wash, a High voltage warning light may turn on the cluster.

12. When washing the fuel cell power mod-ule compartment, is there any potential
risk of electric shock resulting from a
high-voltage short circuit?The FCEV is designed to be a waterproof structure, but please
avoid washing the inside of the compartment if possible. Because
there are many high voltage parts in the power module compart-ment.
13. Can I wash the bottom of the vehicle? Ifyes, what should I be aware of?The FCEV is designed to be a waterproof structure, but please
avoid washing the botttom of the vehicle if possible. Because there
are high voltage cables in the under cover.
14. Can driving with a tire chain affect thedrive motor?Driving with a tire chain causes no direct damage to the drive motor.
15. How should I jump start the vehicle?
Try charging it by pressing the “12V BATT RESET” button first. Refer
to the "If the 12 volt battery is discharged" in this guide book. It it
doesn't work, refer to the "Jump starting" in the Owner's manualchapter 6.