JKBMS Interface and Wiring Guide: Connectors, Ports, Dimensions, and Installation Notes

Quick Summary

JKBMS smart BMS units are designed for lithium battery packs used in electric motorcycles, low-speed electric vehicles, home energy storage, and other LiFePO4 / lithium battery applications. Depending on the model, the BMS may include balance wire connectors, temperature sensor input, RS485 or CAN communication, GPS interface, external display port, activation switch terminals, charging detection terminals, and heating film output.

1. Model Overview and Supported Battery Series

The PDF interface drawings include several Jikong / JKBMS board types. Each board has a different current rating, supported cell count, physical size, and connector arrangement. The table below summarizes the visible specifications from the interface drawings.

Note: Always confirm the exact model number, current rating, battery chemistry, and series count before installation. A similar housing may have different firmware, communication options, or connector definitions.

2. Main Connector Areas on a JKBMS Board

Most JKBMS boards use a clear front-edge connector layout. The large balance connector is used for cell voltage sampling, while smaller connectors are used for temperature sensing, communication, GPS, display, activation, charging detection, and heating functions.

• Temperature sensor port: Usually marked near the temperature probe connector. It is used to monitor battery pack temperature and provide protection logic for over-temperature or low-temperature conditions.
• Balance wire connector: Marked with cell sequence labels such as B1, B2, B3, and up to B17 or B24 depending on the model. This connector collects individual cell voltages for monitoring and balancing.
• RS485 / CAN communication port: Used for communication with external devices, PC tools, controllers, or system-level monitoring devices.
• GPS port: Usually marked with GND, RX, TX, and VCC. It is used for GPS communication or external communication module expansion.
• Display port: Often marked with GND, B, A, and VCC. This interface is used to connect an external display screen or monitoring panel.
• Activation switch port: Often marked as K- and K+. It can be used for an external activation switch or power-on control, depending on model configuration.
• Charging detection / charging correction port: Some high-current boards include CD- and CD+ or dedicated charging detection terminals.
• Heating interface: Some low-speed vehicle models include a heating film interface for low-temperature battery heating systems.

3. Communication Ports: RS485, CAN, GPS, and Display

Communication ports are one of the most important parts of a smart BMS installation. They allow the battery system to exchange data with displays, controllers, monitoring software, and external modules.

RS485 / CAN Port

The RS485 / CAN position is shown as a combined interface in the drawings. The visible notes indicate that the 6P-8P interface is commonly configured as RS485 by default. For CAN communication, the hardware and firmware must support CAN. If the default communication type needs to be changed, confirm the interface type and firmware version before wiring.

Typical labels include GND, A/H, and B/L. In RS485 mode, A and B represent the differential communication pair. In CAN mode, H and L represent CAN High and CAN Low.

GPS Communication Port

The GPS interface is commonly marked as GND, RX, TX, and VCC. The drawing notes indicate that the external 485 module can convert the GPS communication interface into an RS485 interface. This makes it useful for external monitoring, positioning, or data communication expansion.

Display Interface

The display port is typically marked as GND, B, A, and VCC. The interface uses an RS485 electrical standard and is available for users by default. It can be used to read BMS data through the connected display. Some boards also support an external activation button through this display-side interface.

4. Balance Wire Connection Logic

The balance wire harness is responsible for measuring each cell voltage. The drawings show balance terminals arranged in sequence from the pack negative side to each cell positive point. For example, a 24S system may show cell points from 1+ through 24+, while a 17S board may show up to 17+.

In a typical wiring diagram, the BMS connects to the total positive and total negative of the pack:

• B+ total positive: Connected to the battery pack positive bus and to the controller / charger positive line as required by the system design.
• B- total negative: Connected to the battery pack negative bus through the BMS negative power cable.
• Balance leads: Connected in correct cell order. Incorrect sequence may cause abnormal voltage readings or damage.
• Accessory leads: Display, GPS, communication, charging detection, and heating wires should be connected only to their matching ports.

5. Activation Switch, Display Port, and Accessory Interfaces

Some JKBMS boards include a dedicated activation switch interface marked as K- / K+. This interface may be used to wake, activate, or externally control the BMS depending on model configuration. The display port may also support an external activation button in some versions.

When using an external display, confirm the display connector definition before installation. A typical display connector may use GND, B, A, and VCC. Because the display interface may also use RS485 protocol, it is important not to confuse it with the main RS485 / CAN communication port.

6. Heating and Charging Detection Interfaces

The high-current low-speed electric vehicle board drawings show additional interfaces such as heating and charging detection. These are especially important for low-temperature operation and charger-related signal detection.

• Heating interface: Used for a heating film or battery heating system. This helps battery packs operate more safely in cold environments when the system supports heating control.
• Charging detection: Used to detect charging status or charger-related signals. The drawings show labels such as CD- and CD+ on some connector definitions.
• Charging correction / auxiliary power: Some wiring diagrams include notes for charging detection signal, charger communication, or auxiliary power wiring. Always follow the model-specific manual.

7. Choosing the Right JKBMS Board

When selecting a JKBMS board, do not choose only by current rating. The correct model depends on battery series count, maximum continuous current, communication requirements, installation space, display requirements, heating function, and whether the battery pack is used for traction, storage, or general power applications.

8. Installation Checklist

1. Confirm the battery chemistry, total series count, and system voltage.
2. Check that the selected JKBMS model supports the required cell count and current rating.
3. Verify every balance wire sequence with a multimeter before plugging the connector into the BMS.
4. Connect B+ and B- according to the official wiring diagram for the specific model.
5. Connect the temperature sensor to the correct temperature port.
6. Connect RS485 / CAN only after confirming the protocol type and pin definition.
7. Connect GPS, display, activation switch, charging detection, and heating interfaces only if the system requires them.
8. After wiring, power on the system and check voltage readings, temperature readings, communication status, and alarm status before connecting heavy loads.

Need the Full Interface Drawings and Manuals?

The diagrams in this guide are intended to help users understand the general connector layout and wiring logic of JKBMS lithium battery protection boards. For exact wiring, connector definitions, software setup, protocol documents, and model-specific manuals, always refer to the official download files before installation.

If you are unsure which interface or protocol your BMS supports, contact technical support before connecting external equipment.