Jiangsu Niu Electric Technology N1S Manual

小牛电动
Niu Electric
N1S
Operation & Maintenance
Manual for
Electric Scooter N1S
Jiangsu Niu Electric Technology Co. Ltd

小牛电动
Niu Electric
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 not 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.
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 liquid tanks, springs or
other energy storage components. Eye protection devices should be worn as long as there are
suspicious conditions.

小牛电动
Niu Electric
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.

小牛电动
Niu Electric
- 1 -
Contents
Contents - 1 -
Foreword - 2 -
General Information - 3 -
Scooter body/scooter body panel - 9 -
Maintenance - 17 -
Front wheel/front suspension - 23 -
Rear wheel/rear suspension - 31 -
Braking system - 36 -
Lithium battery/charger - 47 -
Motor/controller/accelerator handle (Hall cable sensor) - 56 -
Lighting/instrument/switch - 67 -
Failure code diagnosis - 92 -
Circuit diagram - 97 -

小牛电动
Niu Electric
- 2 -
Foreword
Key points in maintenance of Niu N1S 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.
Jiangsu Niu Electric Technology Co. Ltd

小牛电动
Niu Electric
- 3 -
General Information
Maintenance Rules - 4 -
Scooter Identification - 6 -
Overall specifications - 7 -
Specifications of the motor controller system - 7 -
Specifications of the battery/charger - 7 -
Specifications of the braking system - 8 -
Specifications of the lighting/instrument/switch - 8 -

小牛电动
Niu Electric
- 4 -
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
9 The oil seal should be installed by lubricant application into the oil seal groove, and should be
checked for smoothness, smoothness and damages before installation.
10 The spherical bearings (on the front wheel-hub or rear wheel motor) should be removed by holding
one or two bearing races (the inner and outer races) with tools. The bearing may be damaged in removal
if the force is applied only to one race (the inner or outer race) and thus must be replaced.
Cable connector inspection
The bearing can be broken in the following two
cases

小牛电动
Niu Electric
- 5 -
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.

小牛电动
Niu Electric
- 6 -
Scooter Identification
The scooter frame identification code is made on the rear frame at rear seat cask.
The frame nameplate is riveted above the dual supports at right side of the frame.
The anti-altering is at inner right side of the seat cask.
The motor code is made at left side of the wheel-hub motor.
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.

小牛电动
Niu Electric
- 7 -
Overall specifications
Item
Specifications
Dimensions
Length × width × height
1800×700×1130 mm
Wheelbase
1280mm
Complete vehicle kerb mass
90Kg
Ground clearance of the seat
cushion
740mm
Ground clearance
140mm
Scooter frame
Type of the scooter frame
The pedal type made with combined welding
of panels and pipes
Specifications of the front tire
90/90-12
Type of the front rim
2.15 X12 aluminu m al loy rim
Air pressure of the front tire
175KPa
Specification of the rear tire
120/70-12
Type of the rear rim
3.50 X12 rim mo tor
Air pressure of the rear tire
250KPa
Suspension
Front shock absorber
Telescopic type with 31mm dual hydraulics
Rear shock absorber
Telescopic type with dual hydraulic springs
Brake
Type of the front brake
Hydraulic brake with dual pistons at one side
Type of the rear brake
Specifications of the motor controller system
Item
Specifications
Motor
Motor type
Brushless permanent-magnet motor
Control method
FOC vector control
Rated voltage
DC60V
Rated power
1200W
1500W
Maximum motor power
2000W
2400W
Maximum motor torque
110N*m
120N*m
Controller
Rated voltage
DC60V
Undervoltage protection
52±1V
Maximum current of the controller
35A
40A
Specifications of the battery/charger
Item
Specifications
Battery
Type
Enclosed lithium battery
Rated voltage
60V
Rated capacity
20Ah-30Ah
Charger
Rated output voltage
69.7V
Rated output current
3-4A

小牛电动
Niu Electric
- 8 -
Specifications of the braking system
Item
Standard value (mm)
Usability limit(mm)
Diameter of the front brake disc
φ220mm
-
Thickness of the front brake disc
4.0
3.0
Thickness of the front hydraulic
brake pad
4.0
3.0
Dedicated brake liquid
DOT3 or DOT4
Diameter of the rear brake disc
φ180mm
-
Thickness of the rear brake disc
3.5
2.5
Thickness of the rear hydraulic
brake pad
4.5
3.0
Dedicated brake liquid
DOT3 or DOT4
Specifications of the lighting/instrument/switch
Electric system
Item
Specifications
Front headlight
12V LED
Turn signal lamp
12V LED
Rear tail lamp
12V LED
Brake lamp
12V LED
Instrument
12V LCD instrument panel
Central control unit
12V
USB charging interface

小牛电动
Niu Electric
- 9 -
Scooter body/scooter body panel

小牛电动
Niu Electric
- 10 -
Position of the scooter body panel
（1）Windshield (2) Front journal lid (3) Front panel (4) Front fender bushing (5) Side panel
（6）Side strip (7) Rear bottom fork (8) Rear fender (9) scooter body cover (10) Rear Handrail
（11）Saddle (12) Front glove compartment (13) Central guard (14) Battery compartment cover
(15) Pedal

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Niu Electric
- 11 -
1. Front Fender 2. Pedal 3. Left side strip 4. Left front panel 5. Battery pedal 6. Left foot guard
7. Left scooter body 8. Right foot guard 9. Central guard 10. Right scooter body 11. Seat cushion
0 12. Front journal lid 13. Glove compartment 14. Panel 15. Right front panel 16. Right side strip
* 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.
Do not damage components of a covering
part when it is being installed.

小牛电动
Niu Electric
- 12 -
scooter body coverage
Remove the scooter body in the following sequence
Battery pedal→Foot pedal→Left side strip/right side strip→Front journal lid→Panel→Left front
panel/right front panel
Seat cushion→Central guard→Seat cushion assembly→Left foot guard/right foot guard→Left scooter
body/right scooter body
* 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.

小牛电动
Niu Electric
- 13 -
Maintenance Information
Overview
Procedures for removal and installation of scooter body panels are described in this section.
The ignition switch and air switch must be turned to OFF before disconnection or connection of electric
units, when the storage battery has been installed onto the scooter.
Windshield
Removal/installation
Remove 3 bolts with washers, and then remove the windshield.
Perform the installing contrary to the removal sequence.
Front journal lid
Removal/installation
Remove 2 screws, and then remove the front journal lid.
Perform the installing contrary to the removal sequence.
Front panel
Removal/installation
Remove 2 screws on the top and
2 expansion screws on the bottom.
Lift up and remove the front panel.
Perform the installing contrary to the removal sequence.
Saddle/storage box
Removal/installation
Open the saddle.
Remove 4 screws from the storage box.
Perform the installing contrary to the removal sequence.

小牛电动
Niu Electric
- 14 -
Charger socket
Removal/installation
Remove the storage box.
Disconnect the white connector with charger socket.
Remove 2 installation screws.
Take the charger socket out of the installation hole.
Central guard
Removal/installation
Remove 3 installation screws.
Remove hooks and lugs of the central guard
from the left and right scooter body covers and foot pedal, and then
remove the central guard.
scooter body cover/tail lamp assembly
Removal/installation
Remove the following components:
Storage box
Rear handrail
Central guard
Disconnect the saddle lock cable from the saddle switch assembly.
Disconnect the tail lamp cable connector.
Tail lamp assembly
Remove 6 installation screws, and then
remove the tail lamp assembly from the scooter body guard.
Removal/installation
Open the battery compartment cover with the storage box key.
Remove 4 connection screws from the battery compartment.
Remove the battery compartment cover.
Perform the installing contrary to the removal sequence.

小牛电动
Niu Electric
- 15 -
Foot pedal
Removal/installation
Remove 4 connection bolts from the foot pedal.
Remove the battery compartment cover.
Side strip
Removal/installation
- Remove the battery cover.
- Remove the foot pedal.
Slide the right side strip slightly towards the rear, and then remove hooks.
Remove the right side strip.
Perform the installing contrary to the removal sequence.
Removal/installation of the left side strip
Same as steps for removal/installation of the right side strip.
Side panel
Removal/installation
- Remove the front panel.
- Remove the battery compartment cover.
- Remove the central guard
- Remove the foot pedal.
- Remove the left and right side strips.
Remove connection screws.
Lift up the right side panel slightly, and remove hooks.
Remove the right side panel.
Perform the installing contrary to the removal sequence.
Removal/installation of the left side panel
Same as steps for removal/installation of the right side panel.
Front glove compartment
Removal/installation
- Remove the battery cover.
- Remove the central guard
- Remove the foot pedal.
- Remove the left and right side strips.
- Remove the left and right side panels.
Remove connection screws.
Remove the lock cover.
Remove the front glove compartment.
The installation steps are contrary.

小牛电动
Niu Electric
- 16 -
Rear fender
Removal/installation
Support at one side
Remove 2 connection bolts at one side.
Remove the rear fender.
Front fender bushing
Removal/installation
Remove 4 left and right connection bolts.
Remove the front fender bushing.
The installation sequence is contrary to the removal.

小牛电动
Niu Electric
- 17 -
Maintenance
Maintenance................................................................................................................................................................
Maintenance Information.......................................................................................................................................
Operation of the accelerator handle.................................................................................................................
Wearing of the brake plate (with the disc brake type)................................................................................
Inspection of the brake handle............................................................................................................................
Brake liquid................................................................................................................................................................
Brake lamp switch....................................................................................................................................................
Inspection of the scooter lamp system and switches................................................................................
Side support...............................................................................................................................................................
Suspension system.................................................................................................................................................
Nuts, bolts and fasteners......................................................................................................................................
Wheels/tires................................................................................................................................................................
Steering column bearing.......................................................................................................................................