Key-Disp KD78C User manual

Contents
Product name and model.............................................................................................................................................................1
Specifications................................................................................................................................................................................1
Appearance and dimension..........................................................................................................................................................1
Function and button definition.................................................................................................................................................... 2
◆Function summary................................................................................................................................................................... 2
◆Button definition......................................................................................................................................................................2
General operations...................................................................................................................................................................... 3
◆Switch the E-bike system ON/OFF..................................................................................................................................................3
◆Display interface.......................................................................................................................................................................3
◆Switch push-assistance mode ON/OFF....................................................................................................................................3
◆Switch lighting ON/OFF............................................................................................................................................................4
◆Assist level selection................................................................................................................................................................4
◆Battery level indicator.....................................................................................................................................................................4
◆Error code indication..............................................................................................................................................................5
General Settings..........................................................................................................................................................................6
◆Trip distance clearance...........................................................................................................................................................6
◆Backlight brightness................................................................................................................................................................6
◆Toggle the unit KM/miles........................................................................................................................................................7
◆Wheel diameter....................................................................................................................................................................7
◆Speed limit............................................................................................................................................................................7
Personalized parameters settings................................................................................................................................................ 8
◆Battery power bar settings...................................................................................................................................................8
◆Assist level settings...............................................................................................................................................................9
Assist level mode.................................................................................................................................................... 9
Assist level ratio settings....................................................................................................................................................9
◆Current limit settings..................................................................................................................................... 9
◆Power assist sensor settings...............................................................................................................................10
PAS direction settings........................................................................................................................................................ 10
PAS sensitivity settings.......................................................................................................................................................10
PAS magnet quantity settings............................................................................................................................................11
◆Speed sensor settings........................................................................................................................................11
◆Throttle function settings...................................................................................................................................11
Throttle- 6km enable/disable settings...............................................................................................................................12
Throttle-PAS enable/disable settings................................................................................................................................ 12
◆System setting.............................................................................................................................................13
Battery power delay time settings.....................................................................................................................................13
Button- 6km enable/disable settings.................................................................................................................................13
Slow start up settings.........................................................................................................................................................13
◆Power-on password settings.............................................................................................................................................. 14
Power-on password Enable/Disable..................................................................................................................................14
Power-on password change...............................................................................................................................................15
◆Exit settings.........................................................................................................................................................................15
Factory settings.............................................................................................................................................................15
Appendix 1：Personalized settings symbols........................................................................................................................16
Appendix 2：Other symbols definition......................................................................................................................................17
Quality assurance and warranty scope...................................................................................................................................... 18

Warnings.....................................................................................................................................................................................18

1
Product name and model
E-bike Intelligent LCD display
Model: KD78C
Specifications
●2.0” segment LCD
●24V/36V/48V/52V Power Supply
●Rated working current: 10mA
●The maximum working current: 30mA
●Communication: Uart/CAN
●Operating temperature: -10℃~ 40℃
●Storage temperature: -20℃~ 60℃
Appearance and dimension
Display picture and dimensional info (unit: mm)

2
Function and button definition
◆Function summary
KD78C display has many functions to meet riders’ cycling needs. The indication elements are as
follows:
●Intelligent Battery SOC
●Motor power indicator
●Assist level indicator and adjustments
●Speed indication (incl. current speed, Max. speed and Avg. speed)
●ODO and Trip
●Push-assistance control and indicator
●Trip time
●Backlight on/off and headlight indicator
●Light sensor
●Error code indication
●Various parameter settings (e.g. settings for backlight, Unit, Battery voltage segmented values, PAS level
settings, Password etc.)
●Recover default settings
●Bluetooth function (optional)
KD78C Function layout interface
◆Button definition
KD78C button model is K41 with 4 keys: ON/OFF button, i button, +/light, -/push-assist

3
General operations:
◆Switching the E-bike System On/Off
When battery power is on, the display switches on automatically. when battery power goes out, the display
switches off automatically.
When E-bike system is switched off, display does not use the battery power any more. the leakage current is
less than 1 μA.
■When the E-bike is not in use for 5mins, the E-bike system switches off automatically.
◆Display Interface
After switching on the E-bike system, the display shows current Speed and Trip by default.
Press remote “i” button to switch between indication elements below:
Trip Distance (Km)→ ODO (Km)→ Trip Time (Min.)→ Power (Watts)→Max speed (km/h)→Avg speed
(km/h).
Display indication cycle interface
◆Switching Push-assist Mode On/Off
To activate the push-assist function, press and hold the “-” button. After 2 seconds,
E-bike is activated to go at a uniform speed of less than 6 Km/h while the screen displays . .
When “-” button is released, the e-bike will immediately stop power output and return to the state before
push-assist is engaged.
Push-assistance mode

4
◆Switching Lighting On/Off
Hold +for 2 seconds, display backlight dims and bike headlight is on and headlight icon comes out. Hold +
button for 2 seconds again to switch off the headlight and light icon is gone and display backlight brightness
recovers.
Headlight-on Interface
◆Assist Level Selection
Press "+" or "-" button to switch between the E-bike system assist levels and change the motor output
power. The default assist level mode is 0-5( level “0” to level “5”). The output power is zero on Level “0”.
Level “1” is the minimum output power. The default assist level is level “1”.
Assist level interface
◆Battery level Indicator
The five battery bars represent the capacity of the battery. Five bars are bright when the battery is in full
voltage. When the battery is in low voltage, battery frame will flash at the frequency of 1HZ to give a notice that
the battery needs to be recharged immediately.
Battery level indicator interface
Flash (low voltage)

5
◆Motor Power Indicator
The watts value of the motor can be read via interface below by digits.
Motor power interface
◆Error code indication
The components of the E-bike system are continuously and automatically monitored.
When an error is detected, the error code comes out and malfunction icon shows. The whole interface is
code plus error indication icon.
Error code interface
■Have the display inspected and repaired when an error code appears. Or else, you will not be
able to ride the bike normally. Please always refer to an authorized bicycle dealer.

6
General Settings
At the normal display interface, hold both ‘+’ and ‘-’ simultaneously for 2 seconds to enter General Settings.
▉All the Settings are done to a parked E-bike. Please refer to attached list 2 for the symbol definition.
◆Trip Distance Clearance
TC represents trip distance clearance setting.
To clear trip distance, press “+” button or “-” button to select Yes or No. Yes represents clearing a trip
distance. No represents not clearing a single ride distance.
To store a changed setting, press the “i” button and then access Backlight Brightness Settings.
Trip distance clearance interface
◆Backlight settings:
bL represents backlight settings. Level “1” is the lowest brightness. Level “2” is the standard brightness. Level
“3” is the highest brightness. The default value is “1”.
To change the backlight brightness, press the +/- button to increase or decrease until the desired brightness
level is displayed.
Press ibutton to store a changed setting and then access unit toggling settings.
Backlight settings interface

7
◆Toggle the unit KM/Mile
Urepresents unit settings, “1” is mile and “2” is kilometer. The default value is “2”.
To toggle the unit, press the +/- button to switch between KM/Mile for the speed and mileage.
Press the ibutton to store a changed setting and then access trip distance clearance setting again
or hold the ibutton for 2s and exit General Settings.
Miles and KM toggling interface.
★At General Settings page, hold i button ad - button for over 2 seconds to enter the wheel set and
speed limit set.
◆Wheel size set
Ld means wheel size，settable values are：16”,17”,18”,19”,20”,21”, 22”,23”,24”,25”,26”,700C，28”。Press+/-
to choose the desired wheel size to correctly show the speed and mileage on the display. Press i button to store a
changed set and access to the next set interface.
Wheel size interface
◆speed limit set
LS means top speed limit and the settable range is 12 km/h to 40km/h. press +/- to set the values and
press i button to confirm the setting.
Speed limit interface