niu Kick Scooter KQi3 User manual

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Kick Scooter KQi3
Service Manual
Jiangsu Niu Electric Technology Co. Ltd

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Contents
Foreword
2
Part Names
6
Scooter Identification
7
Overall specifications
8
Parts Removal and Installation Procedure
11
Preparation
11
forehead body
12
dashboard and dashboard cover
14
headlamp
18
handlebar
21
pedal
28
controller and battery pack
32
rear wheel and rear wheel fender
46
folding parts
50
front fork and front wheel
54
Wiring Diagram
59
Fault Codes
60

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Foreword
Key points in maintenance of Niu KQi3 are described in this maintenance manual.
Preparations in the maintenance manual include notes to all operations. Please read the manual
carefully before operating.
Key points in the inspection and adjustment, including maintenance methods for scooter safety and
component performance that are applied from regular examinations, are described.
Chapters are edited with disassembly diagrams, system figures and instructions about the maintenance
and failure diagnosis.
Note:
Modifications of scooter version or structure as well as photos, pictures or instructions in the manual are
referred to physical objects without further notice.
Maintenance Information
The maintenance and reparation information contained in this manual is for technical specialists only.
Maintenance or reparation performed by those who are not trained properly and provided with
appropriate tools and equipment may cause injuries to themselves or others and also lead to damages
or unsafe conditions of the scooter.
The proper maintenance and reparation procedures, some of which require special tools and equipment,
are described in this manual. The risks in terms of personal safety and scooter operation safety, which
may be resulted from the use of components, maintenance procedures or tools not recommended by
Niu must be verified.
Please make replacement with original electric components made by Niu or equivalents that have
corresponding part numbers. We strongly recommend you not to use inferior components.
Customer Safety Notice
The proper maintenance is crucial for customer safety and scooter reliability. Any errors or omissions in
scooter maintenance may result in operating malfunctions, scooter damages or injuries.
Improper maintenance or reparation may lead to unsafe conditions under which serious injuries or even
death of your customers or other people may be incurred.
Please carefully follow the procedures and cautions in this manual and other maintenance materials.
Personal Safety Notice
This manual is used only by professional maintenance technicians, and the warning information about
multiple basic workshop safety operation procedures (such as the procedure that requires gloves when
working on hot components) is n=ot set forth herein. We recommend you not to carry out procedures
specified in this manual without readiness if you have not received the workshop safety training or
grasped the knowledge about maintenance safety specifications.
The following are listed as several most importance general notes to maintenance safety. However, we
are unable to set forth the warning for each of risks that may arise from maintenance and reparation
procedures. You have to determine at your discretion whether a detail task should be implemented.
Failure to properly follow relevant instructions and notes may result in serious injuries or even death.
Please carefully follow procedures and notes in this manual

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Maintenance Rules
1. Metric tools should be made as available as possible in the maintenance of the scooter. Use of improper
tools may damage the scooter.
2 Clean off the dirt outside parts or assemblies of the chassis or braking system before guard removal from
the scooter or opening for maintenance.
3 Please clean parts and blow them with an air compressor after removal and before measurement of the
wearing value.
4 Rubber parts that have become aged or deteriorated are very easy to be damaged by the solvent or oil.
They should be checked or replaced if necessary before reassembly.
5. Multiple assemblies should be loosened in the sequence from outside to inside and beginning with small
ones.
6. Complex assemblies should be stored in a proper installation sequence for further assembling.
7 Extra attention should be paid to important fitting positions before disassembling. Parts that are no longer
to be used should be replaced before disassembly.
8 The bolt or screw length varies with assemblies and guards. Bolts or screws must be installed at correct
positions. A bolt can be placed into a bolt hole for fitness in case of confusion.
Important notes
1．Please use original parts made by Niu. Use of components that are not in compliance with design
specifications by Niu Company may cause damages to the scooter.
2．Maintenance operations can be performed only with metric tools. The metric bolts, nuts and screws can
not be interchanged with British fasteners.
3．The replacement with new washers, O rings, split pins and lock shims should be made for reassembly.
4．Bolts or nuts should be tightened by beginning with large-diameter bolts or inward bolts and then
gradually tightening to specified torques diagonally, unless otherwise indicated.
5．Clean components that have been removed with the detergent solution. All the sliding faces should be
lubricated before assembling.
6．Check all components for the proper installation and operating after assembly.
7．Remove the dirt and oil stains before measurement. Apply recommended lubricants to sections to be
lubricated during assembly.
8．Apply the lubricant to part surfaces to avoid rusting and dust accumulation, if the engine and transmission
systems need to be stored for a long time after disassembling.
Cable connector inspection
•Loose cables constitute a risk to electric safety. Cables should be checked after their clamping to ensure
electric safety.
•Bending of cable clamps towards welding points is not allowed.
•Cables are bound at designated positions.
•Cable placement at the scooter frame end or a sharp angle is not allowed.
•Cable placement at the bolt or screw end is not allowed.
•Cable placement should be made away from thermal sources or positions where cables may be stuck in
moving.
•The cable placement along stem handles should not be made too tight or loose and should not interfere
with adjacent parts at any steering positions.
•Cables should be placed smoothly without being twisted or tied.
•Verify whether the connector shroud is damaged or the connector is excessively open before connecting.
•Please protect the cable at a sharp angle or turning position with adhesive tapes or a hose.
•Cables should be bound reliably with adhesive tapes after reparation.
•Controlling cables should not be bent or twisted. The controlling would not be flexible if controlling cables
were damaged.

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Importance Safety Notes
Make sure that you have completely understood basic workshop operation safety
procedures and taken on proper protective clothes and are provided with safety
equipment. Extra attention should be paid to the following in the implementation of a
maintenance task:
•Read all the relevant instructions before operation, and make sure that you have
necessary tools, spare parts, components and skills to implement a maintenance task
safely and completely.
•There are high-voltage circuits in the scooter system, which can cause electric shock. It
must be verified that your maintenance site, tools, protective equipment and operation
procedures are in compliance with the insulation requirement.
•Eyes should be protected with proper safety glasses, goggles or masks in operations
such as hammering, drilling, polishing or prying or working around high-pressure air or
fluid tanks, springs or other energy storage components. Eye protection devices should
be worn as long as there are suspicious conditions.
•Other protection devices such as gloves or safety shoes are used where necessary.
Gloves should be worn before handling of a hot or sharp component that may cause
serious burns or cuts or grasping of any things that may cause injuries.
•Measures should be taken to protect you and others once a scooter is lifted. Make sure
that the scooter is always supported stably when being lifted with a crane or jacks.
Please use jack mounts.
•The hot motor after driving for a long time may cause burns. Wait for the motor to
cool down before working on it.
•Moving parts can cause injuries. Make sure that your hands, fingers and clothes are not
obstructive.
•Components must be cleaned with non-flammable solvents instead of the gasoline.
•All components related to a storage battery should be away from cigarettes, sparks and
flames.

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Part Names
l Vehicle Diagram with Part Names
Front
windshield Dashboard Bell
Left handlebar grip
Leftdisc brake lever
Reflector
Folding parts
Headlamp
Front reflector
Right disc
brake lever
Right handlebar grip
Folding latch
Front fork protection
cover
Tyre
Disc brake plate
Front wheel
Front brake
line
Lock components
Foot pad
pedal trim
Bottom cover
Disc brake
caliper
Side stand
Rear tail lamp
Rear wheel fender
Tyre
Disc brake calipers
Disc brake plate
Rear axle trim cover
Motor and Tyre assembly

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Scooter Identification
•Vehicle serial number (SN) is in the user manual
•The scooter frame identification code (VIN) is made inside the frame.
The motor code is made at left side of the wheel-hub motor.

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Parameter Name
KQi3 Pro
KQi3 Sport
Remarks
Length
1,173mm
1,173mm
Width
541.5mm
541.5mm
High
1,202mm
1,202mm
Length after folding
1,173mm
1,173mm
Width after folding
541.5mm
541.5mm
Height after folding
504mm
504mm
Axle distance
890mm
890mm
Ground clearance
76mm
76mm
Pedal height
169mm
169mm
Handle height
1,157mm
1,157mm
Angle of folding riser to
vertical distance
15°
15°
Endurance mileage
Not less than 50KM
Not less than 40KM
25℃, without
wind, 75kg body
weight, flat
asphalt road,
measured at a
constant speed of
15km/h
Turning radius
Minimum turning
radius≤1.3m when
walking your scooter
Minimum turning
radius≤2.5m at a speed
of 10km/h
Minimum turning
radius≤3m at a speed of
12.5km
Minimum turning
radius≤1.3m when
walking your scooter
Minimum turning
radius≤2.5m at a
speed of 10km/h
Minimum turning
radius≤3m at a speed
of 12.5km
Climbing ability (slope)
20% (slope)
15%
Condition: 75kg,
riding uphill at a
constant speed of
8±2km/h, driving
distance not less
than 5m
Overall specifications：

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Overall specifications：
Parameter Name
KQi3 Pro
KQi3 Sport
Allowable height of surface
gathered water
≤65mm
≤65mm
Operating temperature of
scooter
-10 - 45°C
-10 - 45°C
Battery capacity and
specification
486.7Wh (10.4AH) lithium battery
365WH (7.8AH) lithium battery
Full charging time
6H
5h
Charging temperature range
Usable temperature range (0-40℃)
Optimal temperature range (10-35℃)
Usable temperature range (0-40℃)
Optimal temperature range (10-35℃)
Maximum battery storage time
(50% electric quantity)
State as delivered (50% electric
quantity) up to 180 days
Battery exhausted state <60 days
State as delivered (50% electric
quantity) up to 180 days
Battery exhausted state <60 days
Brake method
Front- and rear-wheel dual
mechanical disc brakes/rear wheel
electronic brake
Front wheel mechanical disc
brakes/rear wheel electronic brake
Braking distance
Double brake:≤4.4m (at a running
speed of 20Km/h)
Double brake:≤4.4m (at a running
speed of 20Km/h)
Headlight
Short-distance beam 6v 3w±15%,
position 12v 2.26w±15%
Short-distance beam 6v 3w±15%,
position 12v 2.26w±15%
Small bell
Percussion bell
Percussion bell
Motor rated power
350W
300W
Battery capacity
46.8V 486.7Wh
46.8V 365Wh
Driving mode
Rear drive
Rear drive
Waterproofing grade
Finished scooter IP54, battery pack
(itself) IPX7, controller (itself) IPX7,
motor IPX5
Finished scooter IP54, battery pack
(itself) IPX7, controller (itself) IPX7,
motor IPX5

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Overall specifications：
Structure division
KQi3 Pro
KQi3 Sport
Weight
information
Net weight
20.3KG
18.4KG
Gross weight
25.6KG (56.4lbs)
23.7KG (52.2lbs)
Tyre
Size of front wheel
9.5 inches (241mm)
9.5 inches (241mm)
Tyre type
Rubber vacuum tyre
Rubber vacuum tyre
Inflation pressure
50-60psi (shipping status)
50-60psi (shipping status)
disc brake plate
120mm diameter brake disc
120mm diameter brake disc
Body part
Folding mechanism
Two stage protective folding
mechanism
Two stage protective folding
mechanism
Body material
6061 aluminum alloy + welding
6061 aluminum alloy + welding
Restriction of steering
angle
Left and right 55°
Left and right 55°
Dashboard
Fault warning
Error symbols display on the digital
tube, while warning tone comes from
the buzzer
Error symbols display on the digital
tube, while warning tone comes
from the buzzer
Unit display
Digital display on LED digital tube
(mph and km/h are switchable)
Digital display on LED digital tube
(mph and km/h are switchable)
Speed display
Digital display on LED digital tube
Digital display on LED digital tube
Electric quantity display
Digital display of electric quantity
bar on LED digital tube
Digital display of electric quantity
bar on LED digital tube
Pedestrian mode
"Small foot" shape displays on LED
digital tube
"Small foot" shape displays on LED
digital tube
Battery
Voltage
46.8V
46.8V
Capacity
486.7Wh (10.4AH)
365WH (7.8AH)
Long storage temperature
0°C - 40°C
0°C - 40°C
Motor
Non-zero start
≥4KM/H
≥4KM/H
Controller rated voltage
46.8V
46.8V
Controller current
limiting
17A±1A
14A±1A
Charger
Output current
2.0A max
2.0A max
Output voltage
54.6V (53.5V)
54.6V (53.5V)

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Preparation
Maintenance qualification: Maintenance personnel must receive proper training .
Work environment: Indoor light intensity shall be 1000±200 Lux. The maintenance room
must be isolated from daylight. Light must be evenly dispersed and directed vertically from
above.
The maintenance room must be equipped with fire safety facilities, such as explosion-proof
junction boxes, dry powder fire extinguishers, and fire buckets.
Tools:
Phillips screwdriver bits
PH0/PH1/PH2
Hexagon screwdriver bits
2.5/3/4/5/6 mm
Torx screwdriver bits
Hexagon socket screwdriver bits
15/18 mm
Electric screw driver
With adjustable torque setting (0-50 N.m)
Ratchet wrench
15/18 mm
Valve core remover
(Standard)
Air compressor
150 PSI
Section 1
Storage
Please park your vehicle in a garage or in an open space.
If your vehicle is to be stored for a long time, please protect it from moisture and pressure.
Regularly charge the battery to avoid deep sleep caused by prolonged storage.
Note
• Do not damage scooter body coverages in disassembling/assembling.
• Do not damage hooks and claws on scooter body coverages in disassembling/assembling.
• Align the embedded panels and covers on scooter coverages with their respective grooves.
• Hooks and claws at various sections should be installed properly during assembly.
Procedures for removal and installation of scooter body parts are described in this section.
The ignition switch must be turned to OFF.

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forehead body Section 2
2.1 unsrew four Hexagon socket screws
Related Screws：M5*14（H2001013）
Mount: Follow as the reverse order.
2.2remove the controller harness’line and the
dashboard’line
Mount: Follow as the reverse order. Insert as per
indicated by the waterproof line arrow.

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forehead body
2.3 remover the front brake
line and rear brake line
Mount: Follow as the reverse
order.
2.4 remove the forehead
body
Mount: Follow as the reverse
order.
Section 2

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dashboard and dashboard cover
3.1remover the front windshield:unscrew two Hexagon socket
screws
Related Screws：M5*12（H2001009）
Mount: Follow as the reverse order.There shall be no shaking
clearance while shaking the front windshield with one hand .
Section 3
3.2 remove four silicone plugs，unscrew four Hexagon
socket screws
Related ScrewsM5*18（H2001006）
Mount: Follow as the reverse order.

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dashboard and dashboard cover
Section 3
3.4 remove the dashboard cover：tear off the dashboard
cover
Mount: Follow as the reverse order.
3.3 remove the forehead locking cover
Mount: Follow as the reverse order.Install upwards as
per indicator arrow.

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dashboard and dashboard cover
Section 3
3.5 unscrew three cross screws,remove the dashboard from the
forehead body
Related Screws：M2*8（H2001008）
Mount: Follow as the reverse order.
3.6 cut the fastening tie,remove the harness sleeve
Mount: Follow as the reverse order.

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dashboard and dashboard cover
Section 3
3.7 remove the dashboard：remove four connectors
Mount: Follow as the reverse order.Press the switch button to
power on and check whether the startup is normal.
3.8 separate the forehead body and the handlebar
Mount: Follow as the reverse order.

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headlamp
Section 4
4.1 remove the forehead
midhole plug，Notice that
the side close to the
handlebar shall be with
radian, and the rear shall
be flat.
Mount: Follow as the
reverse order.
4.2 unscrew two Hexagon socket screws
Related Screws：M5*12（H2001009）
Mount: Follow as the reverse order.

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headlamp
Section 4
4.3 remove the headlamp wire plug,remove the
headlamp
Mount: Follow as the reverse order.

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headlamp
Section 4