KEY-DISP KD21C eBike Display User Manual

Product Name and Model

Intelligent LCD display of eBike; model: KD21C.

Specifications

• 24V/36V/48V Power Supply
• Rated working current: 10mA
• The maximum working current: 30mA
• Off leakage current: <1uA
• The supply controller working current: 50mA
• Working temperature: -20℃ ~ 60℃
• Storage temperature: -30℃ ~ 70℃

Appearance and Size

Display appearance and dimension figure (unit: mm)

Color categories: Top shell of the display is two color options, black and white, and bottom shell of the display is only one black.

Function Summary and Button Definition

Function Summary

KD21C can provide a lot of functions to fit the users' needs. The indicating contents are as following:

• Smart Battery indicator
• Motor-output indication
• Assistance-level indication
• Speed indication (incl. running speed, max speed and average speed)
• Trip distance and total distance
• The push-assistance function
• Trip time display of single
• The Lighting On/Off
• Error Code indication
• Various Parameters Settings (e.g. wheel size, speed-limited, battery level bar, assistance level, controller limited current, max speed, password enable, etc.)
• Recover Default Settings

Functional Area Distribution

A diagram shows the functional areas of the display, including Battery Indicator, Function List, Assistance-Level Indication, The Lighting Indicator, Speed Indication, Text Area Indication, Speed Unit, Setting Indicator, and Range/Power Unit.

Button Definition

There are three buttons (M, +, -) on the KD21C display that represented by the following functions respectively: MODE, UP, DOWN.

General Operation

Switching the eBike System On/Off

To switch on the eBike system, hold the MODE button for 2s. To switch off, hold the MODE button for 2s again. The eBike system switches off automatically when parking for more than 10 minutes. The leakage current is less than 1 uA when switching off.

Display Interface

After switching on, the display shows Running Speed and Total Distance, except battery indicator and assistance level. Press the MODE button to cycle through: Running Speed (Km/h) → Trip Distance (Km) → Trip Time (Hour.) → Max Speed (Km/h) → Average Speed (Km/h) → Motor Power (W) → Running Speed (Km/h).

Diagrams illustrate the display interface transitions.

Switching Push-assistance mode On/Off

To access push-assistance mode, hold the DOWN button. The eBike moves at a uniform speed of 6 Km/h, indicated by 'P' on the screen. The function switches off when the DOWN button is released. This function should only be used when pushing the eBike, and danger of injury exists if the wheels do not have ground contact.

Switching the Lighting On/Off

To switch on the display backlight and headlight, hold the UP button for 2s. Hold the UP button for 2s again to switch them off.

Assistance Level Selection

Assistance levels indicate motor output power, ranging from Level "0" (zero power) to Level "5" (maximum power). The default value is Level "1". To change assistance level, press UP/DOWN to increase or decrease until the desired level is displayed. The interface shows "5" or "0" flashing when reaching the maximum or minimum level respectively.

Battery Indicator

Five battery bars represent battery capacity. The battery frame flashes when the battery is in low voltage, indicating it needs recharging.

Error Code Indication

If errors occur in the electronic control system, an error code will appear automatically. Refer to Attached list 1 for error code definitions. Offer the display to a Service Center when an error code appears.

General Settings

After the eBike system is switched on, hold both the UP and DOWN buttons for 2s to access general settings menu.

Trip Distance Clearance

TC represents trip distance clearance setting. To clear trip distance, press UP/DOWN to choose Y or N. The default value is N. To store a changed setting, press MODE and then access backlight contrast settings. Various symbol definitions refer to Attached list 4.

Backlight Contrast settings

bL represents backlight contrast settings. Level "1" is low brightness, Level "2" is middle brightness, and Level "3" is high brightness. The default value is "1". To modify brightness, press UP/DOWN to increase or decrease. To store a changed setting, press MODE and then access unit Conversion Settings.

Unit km/mi Conversion

U represents unit settings. "1" is mile, "2" is kilometer. The default value is "2". To convert unit, press UP/DOWN to increase or decrease. To store a changed setting, press MODE to access trip distance clearance settings. To store and exit general settings, hold MODE for 2s.

General Parameter Settings

To access general parameter Settings, hold both UP and DOWN buttons for 2s, then hold both DOWN and MODE buttons for 2s again.

Wheel Diameter Settings

Ld represents wheel diameter settings. Electable values are 16, 18, 20, 22, 24, 26, 700C and 28. The default value is 20 inch. To change settings, press UP/DOWN to increase or decrease. To store a changed setting and access speed-limit settings, press MODE.

Speed-limit Settings

LS represents the limit speed settings. When the running speed is faster than the limit speed, the eBike system will switch off automatically. Limit speed ranges from 12Km/h to 40Km/h. The default value is 25Km/h. To change settings, press UP/DOWN to increase or decrease. To store a changed setting and exit General Parameter Settings, hold MODE for 2s.

Personalized Parameter Settings

Personalized Parameter Settings can match a variety of requirements. There are 8 Settings items: Battery Power Bar Settings, Power assistant level Settings, Over-current Cut Settings, Power Assistant Sensor Settings, Speed Sensor Settings, Throttle Function Settings, System Settings, and Power-on Password Settings. Refer to Attached list 2.

To access Personalized Parameter Settings, hold both UP and DOWN buttons for 2s, then hold UP and DOWN buttons again. To access a specific settings page, press UP/DOWN to select the item and press MODE.

Diagrams illustrate the options selection interface.

Battery Power Bar Settings

VOL represents voltage settings. Each bar represents a voltage value; 5 bars must be entered one by one. For example, VOL 1 is the first bar voltage value, default is 31.5. Press UP/DOWN to increase or decrease the number. Press MODE to store and access the next bar. Hold MODE after entering all 5 values to confirm and return to the previous menu.

Assistance Level Settings

Assistance Level option: 8 modes available: 0-3, 1-3, 0-5, 1-5, 0-7, 1-7, 0-9, 1-9. The default value is 0-5. To select a mode, press UP/DOWN to increase or decrease. Press MODE to store and access the PAS ratio settings.

PAS Ratio Settings

To modify PAS ratio, press MODE to turn to the next PAS ratio settings. After inputting all PAS ratios, hold MODE for 2s to confirm and return to the previous menu. Refer to Attached list 3.

Controller Over-Current Cut Settings

CUR represents controller over-current cut settings. CUR value can be changed from 7.0A to 22.0A. The default value is 15A. To change settings, press UP/DOWN to increase or decrease the current value. To store a changed setting, hold MODE and return to the previous menu.

Power Assistant Sensor Settings

The Direction of Power Assistant Sensor Settings: PAS represents power assistant sensor settings. "run-F" means forward direction, "run-b" means back direction. The default value is "run-F". To change the direction, press UP/DOWN to select F or b. Press MODE to store and access PAS sensitivity settings.

The Sensitivity of PAS Settings: SCN represents sensitivity. Values range from "2" (strongest) to "9" (weakest). The default value is "2". To change sensitivity, press UP/DOWN to select a value. Press MODE to store and access magnet disk settings.

Magnet quantity Settings: N represents magnet numbers of PAS disk. The default value is 6. To change magnet numbers, press UP/DOWN to select the quantity. Hold MODE to store and return to the previous menu.

Speed Sensor option

SPS represents speed sensor settings. The default value is 1. To change settings, press UP/DOWN to select the quantity of magnet head (range 1 to 9). Hold MODE to store and return to the previous menu.

Throttle Definition

Throttle Push-assistance Enable/Disable: HL represents throttle push-assistance function. HL-N is disabled, HL-Y is enabled. Default is N. To change, press UP/DOWN to select Y. Press MODE to store. Otherwise, select N to access Throttle Level Enable Settings.

Throttle Level Enable/Disable: HF-Y represents throttle level is enabled, HF-N is disabled. Default is N. To change, press UP/DOWN to select Y or N. Press MODE to store and access Throttle Enable Settings. Hold MODE for 2s to return to the previous menu.

System Settings

Delay time settings of battery power: DLY represents delay time settings. Default is 3s. To change, press UP/DOWN to select 3s, 6s, or 12s. Press MODE to store and access max speed limited settings.

Max speed limited: MAX SPD represents max speed limited settings. Default is 40Km/h. To change, press UP/DOWN to set the max speed from 25Km/h to 40 Km/h. Press MODE to store and access Button PAS Settings. This setting is the priority version, the speed is the maximum set by manufacturer.

Button Push-assistance Enable/Disable: PUS represents button push-assistance settings. Y is enabled, N is disabled. Default is Y. To change, press UP/DOWN to choose Y or N. Press MODE to store and access PAS speed settings.

PAS Speed Settings: To change PAS speed settings, press UP/DOWN to adjust from 20% to 35%. Default is 25%. Press MODE to store and access slowly start up settings.

Slowly Start up Settings: SSP represents slowly start up. Range is "1-4", "4" is the slowest. Default is "1". To change, press UP/DOWN to select the desired value. Press MODE to store and turn to Delay time settings of battery power page. Hold MODE for 2s to return to the previous menu.

Power-on Password Settings

P2, 0000 on the screen means power-on password settings. Default is 2222. To access settings, press UP/DOWN to modify the value and press MODE to confirm each digit until the 4-digit password is completed. Press MODE to access power-on password enable settings.

Power-on Password Enable/Disable

To change settings, press UP/DOWN to select Y or N. If Y, press MODE to access power-on password modify interface; otherwise, exit. Default is N. Y is power-on password enable, N is power-on password disable.

Power-on Password Modify

When the display shows P3, 0000, press UP/DOWN to modify the value and press MODE to confirm each digit until the new 4-digit password is completed. Hold MODE for 2s to store and exit settings. The next time the eBike system is switched on, the display will show P1,0000, prompting for the new password.

Exit settings

In the settings state, pressing MODE confirms input and stores settings, then exits. Holding DOWN cancels the operation without storing data and returns to the previous menu. If there are no operations for one minute, the display exits the settings state.

Recover default settings

dEF represents recover default settings. Default is N. To access, hold UP and MODE for 2s, then press UP/DOWN to choose Y or N. N means do not recover, Y means recover. Hold MODE for 2s when Y is selected to recover default settings. The display shows DEF-00 and returns to the general display state.

Operation Cautions

Be careful of safe use. Do not attempt to release the connector when the battery is on power. Try to avoid hitting. Do not modify system parameters to avoid disorder. Make the display repaired when an error code appears.

Quality assurance and warranty scope

Warranty

1. The warranty is valid only for products used in normal usage and conditions.
2. The warranty is valid for 24 months after shipment or delivery.

Other items

The following items are not covered by warranty:

• The display is demolished.
• Damage caused by wrong installation or operation.
• Shell of the display is broken when out of the factory.
• Wire of the display is broken.
• Beyond Warranty period.
• Fault or damage caused by force majeure (e.g., fire, earthquake, etc.).

Connection layout

Connector line sequence:

Diagrams show the Display-side Connector, Display-side adapter, and Switch wiring, illustrating the pin connections.

Line sequence table:

Some wire uses a water-proof connector, so the inside color cannot be seen.

Attached list 1: Error code definition

Attached list 2: Personality Parameter settings

Attached list 3: Power assist table

Attached list 4: symbol definition