1. Introduction
The JIKONG JK-B2A20S20P Smart Battery Management System (BMS) is an intelligent protection board designed for large-capacity series lithium battery packs. It offers comprehensive management and protection features for Li-ion, LiFePo4, and LTO battery types. This manual provides detailed instructions for the installation, operation, and maintenance of your Smart BMS.
2. Key Features
The JIKONG Smart BMS incorporates advanced active balancing technology and a robust design to ensure optimal battery performance and longevity. Key features include:
- Voltage Acquisition: High-precision voltage acquisition (±3mV).
- Current Acquisition: High-precision current acquisition.
- Active Balancing: High current active balancing (1A/2A continuous) for improved battery consistency and extended lifespan.
- Comprehensive Protection: Overcharge, over-discharge, overcurrent, over-temperature, low-temperature protection, and short-circuit protection.
- Coulomb Meter: Accurate battery capacity calculation.
- Communication Interfaces: Supports Bluetooth communication (for mobile APP), RS485 (optional), CAN (optional), and UART (for GPS).
- Display Support: Compatible with external display screens for real-time battery information.
- Heating Function (Optional): For low-temperature environments to maintain battery activity.
- Alarm Function (Optional): Alerts for safety risks.
- Battery Parallel Function (Optional): For energy storage applications.
- ACC Detection Function (Optional): For enabling discharge.
- Intelligent Sleep Mode: Reduces power consumption during standby.
- Emergency Switch: Provides a temporary override for critical situations.
3. Specifications
The JIKONG JK-B2A20S20P BMS is available in 150A and 200A versions. The following table details the general specifications. For specific model configurations, refer to the product selection guide in the official PDF manual.
3.1. General Parameters (150A Protection Board)
| Parameter | Value | Unit |
|---|---|---|
| Supply Voltage | 20-100 | V |
| Operating Power Consumption | <800 | mW |
| Operating Temperature | -30 to 70 | °C |
| Max Number of Collection Strings | 24 | Strings |
| Max Balancing Current | 1 or 2 | A |
| Max Charging Current | 150 | A |
| Max Discharge Current | 150 | A |
| Max Instantaneous Current | 300 | A |
| Max Internal Loop Resistance | 0.365 | mΩ |
| Protective Plate Size | 162*102*20.4 | mm |
| Finished Weight | 560 | g |
3.2. General Parameters (200A Protection Board)
| Parameter | Value | Unit |
|---|---|---|
| Supply Voltage | 20-100 | V |
| Operating Power Consumption | <800 | mW |
| Operating Temperature | -30 to 70 | °C |
| Max Number of Collection Strings | 24 | Strings |
| Max Balancing Current | 2 | A |
| Max Charging Current | 200 | A |
| Max Discharge Current | 200 | A |
| Max Instantaneous Current | 400 | A |
| Max Internal Loop Resistance | 0.275 | mΩ |
| Protective Plate Size | 162*102*20.4 | mm |
| Finished Weight | 560 | g |
3.3. Default Parameters
The following table provides default parameter settings for various battery types (Li-ion, LiFePo4, LTO). These can be adjusted via the mobile APP.
| Parameter | Li-ion (Default) | LiFePo4 (Default) | LTO (Default) | Unit |
|---|---|---|---|---|
| Balancing Initial Voltage | 3 | 3 | 2 | V |
| Max Balancing Current | 1 or 2 | 1 or 2 | 1 or 2 | A |
| Unit Overcharge Voltage | 4.2 | 3.6 | 2.7 | V |
| Single Overcharge Protection Recovery | 4.18 | 3.55 | 2.65 | V |
| Monomer Undervoltage Protection | 2.82 | 2.6 | 1.8 | V |
| Single Undervoltage Protection Recovery | 2.85 | 2.65 | 1.85 | V |
| Automatic Shutdown Voltage | 2.8 | 2.5 | 1.7 | V |
| SOC-0% Voltage | 2.9 | 2.6 | 1.85 | V |
| SOC-100% Voltage | 4.18 | 3.5 | 2.65 | V |
| Trigger Balancing Differential Pressure | 0.01 | 0.01 | 0.01 | V |
| Charging Overcurrent Protection Delay | 30 | 30 | 30 | S |
| Charging Overcurrent Protection Release Time | 60 | 60 | 60 | S |
| Discharge Overcurrent Protection Delay | 300 | 300 | 300 | S |
| Discharge Overcurrent Protection Release Time | 60 | 60 | 60 | S |
| Short-circuit Protection Delay | 5 | 5 | 5 | µS |
| Short-circuit Protection Release Time | 30 | 30 | 30 | S |
| Charging Overtemperature Protection Temperature | 70 | 70 | 70 | °C |
| Charging Overtemperature Restore Temperature | 60 | 60 | 60 | °C |
| Discharge Overtemperature Protection Temperature | 70 | 70 | 70 | °C |
| Discharge Overtemperature Recovery Temperature | 60 | 60 | 60 | °C |
| Charging Low Temperature Protection Temperature | -20 | -20 | -20 | °C |
| Charging Low Temperature Restore Temperature | -10 | -10 | -10 | °C |
| MOS Overtemperature Protection Temperature | 100 | 100 | 100 | °C |
| MOS Overtemperature Recovery Temperature | 80 | 80 | 80 | °C |
| Device Address | 0 | 0 | 0 | / |
3.4. Physical Dimensions
The JIKONG BMS features a fully aluminum alloy shell for superior heat dissipation and durability, offering dustproof, waterproof, anti-voltage, and anti-vibration properties.
4. Setup and Installation
4.1. Packing List
Before installation, verify that all components are present:
- BMS Unit x 1
- Switch x 1 (long 50cm)
- NTC x 1 (long 40cm)
- Sampling line B x 1 (long 70cm)
- Sampling line A x 1 (long 70cm)
4.2. Wiring Instructions
The JIKONG JK-BxAxxS-15P/20P series protection board is suitable for 7-24 series lithium battery packs. The wiring method varies depending on the number of cells in your battery pack. Always ensure all cables are connected correctly before powering on.
- Connect all the balance cables to the BMS.
- Insert the main cable into the BMS.
- Connect the B-line (total negative electrode) and the P-line (total positive electrode) to the battery.
Important Safety Note: Before starting the protection board, double-check that the balance cable is properly connected and that P- and B- are correctly connected. Ensure the protection board is securely fixed with the battery core. Incorrect connections can lead to abnormal operation or even damage.
4.2.1. Wiring for 24-String Cells
4.2.2. Wiring for 16-String Cells
4.3. Interface Definitions
The BMS provides various interfaces for communication and control. Refer to the following table for pin definitions of the main connectors.
| Connector | Pin No. | Pin Name | Definition |
|---|---|---|---|
| P1 (XH-15AW) Balance & Acquisition Interface | 1 | B- | Total negative battery |
| 2 | B1 | The first battery positive | |
| 3 | B2 | The second battery positive | |
| ... | ... | ... | |
| 15 | B14 | The fourteenth battery positive | |
| 16 | B15 | The fifteenth battery positive | |
| P2 (XH-11AW) Balance & Acquisition Interface | 1 | B16 | The sixteenth battery positive |
| ... | ... | ... | |
| 9 | B23 | The twenty-third battery positive | |
| 10 | B24 | The twenty-fourth battery positive (Total battery positive) | |
| 11 | B+ | Protection board power supply, connected to the battery | |
| P3 (XH-4AW) Temperature Interface | 1 | T1A | First temperature sensor pin A |
| 2 | T1B | First temperature sensor pin B | |
| 3 | T2A | Second temperature sensor pin A | |
| 4 | T2B | Second temperature sensor pin B | |
| P4 (A1254WF-4A) Communication Interface | 1 | CAN_L | CAN signal negative terminal |
| 2 | CAN_H | CAN signal positive terminal | |
| 3 | RS485_A | RS485 signal positive terminal | |
| 4 | RS485_B | Negative terminal of RS485 signal | |
| P5 (1.25T-4PWT) UART Interface | 1 | GND | Power/signal ground |
| 2 | RX | UART RX, 3.3V | |
| 3 | TX | UART TX, 3.3V | |
| 4 | VGPS | Power output, voltage close to B+ | |
| P6 (A1254WF-6A) Display Interface | 1 | K- | Activation signal negative electrode |
| 2 | K+ | Activate the positive signal | |
| 3 | GND | Negative terminal | |
| 4 | B | Display RS485 signal negative | |
| Heating Wire | 1 | HT- | Heater element negative electrode |
| Bluetooth Connection Indicator | Steady on when connected, blinking when disconnected. | ||
| P- | Connect to external load or negative terminal of charger | ||
| B- | Connect to the negative battery terminal | ||
5. Operation
5.1. Device Activation
The BMS does not have a physical power-on control switch. It is designed for charging activation mode. After the battery assembly is complete, connect the charger (with a voltage 2V higher than the battery voltage) to activate the BMS.
Alternatively, if you have an optional display screen and button, you can activate the BMS by inserting the cable into the display interface and pressing the button.
5.2. Mobile APP and PC Software
The JIKONG Smart BMS supports a mobile APP for iOS, Android, and HarmonyOS, allowing you to monitor battery status and adjust parameters via Bluetooth. PC software is also available for more detailed configuration and monitoring.
To download the mobile APP, scan the QR code below. Android Version 7 or higher is required.
5.3. Active Balancing
The BMS uses energy transfer active balancing to move energy from high-voltage cells to low-voltage cells, ensuring battery consistency. You can set the balance trigger pressure difference (mV) in the APP. Balancing automatically activates when the voltage difference between any two strings exceeds the set value and stops when it falls below the set value. The default balance current is 1A/2A, adjustable based on battery capacity.
5.4. Communication Functions
The BMS supports optional CAN and RS485 functions. You can select CAN or RS485 for multiplexed ports on the BMS control page of the APP. The address and communication protocol can be configured according to your requirements. Refer to the JIKONG Protection Board communication protocol document for specific details.
The BMS is compatible with mainstream inverter communication protocols in the market, including Deye, Pylontech, Growatt, Victron Energy, INVT, Goodwe, SMA, and Srne.
6. Maintenance
6.1. Overvoltage Protection (Charge)
The BMS includes standard charge overvoltage protection. You can set the single overcharge protection voltage and recovery voltage in the APP. If any cell voltage exceeds the set value during charging, the BMS will stop charging. Charging resumes when all cell voltages fall below the recovery voltage.
6.2. Undervoltage Protection (Discharge)
Standard discharge undervoltage protection is included. Set the battery undervoltage protection voltage, recovery voltage, and automatic shutdown voltage in the APP. If any cell voltage drops below the protection value during discharge, the BMS will stop discharging. Discharge resumes when all cell voltages rise above the recovery voltage. If any cell voltage drops below the automatic shutdown voltage, the BMS will automatically shut down.
6.3. Overcurrent Protection (Charge & Discharge)
The BMS features standard charge and discharge overcurrent protection. You can set continuous current, overcurrent delay, and overcurrent release time in the APP. If the current exceeds the set continuous current for the specified delay, the BMS will stop charging/discharging. Operation resumes after the overcurrent release time.
Note: The maximum continuous discharge current should not exceed the nominal current of 150A/200A.
6.4. Overtemperature Protection
Standard charge and discharge overtemperature protection is included. Set the protection and recovery temperatures in the APP. If the temperature exceeds the set protection value, the BMS will stop operation. Operation resumes when the temperature falls below the recovery value.
6.5. Low Temperature Protection (Charge)
Standard charge low-temperature protection is included. Set the protection and recovery temperatures in the APP. If the temperature falls below the protection value, the BMS will stop charging. Charging resumes when the temperature rises above the recovery value. For extremely cold environments, consider using the optional heating function.
The optional heating function uses a resistance heater or heating film to warm the battery at low temperatures. The designed heating current is 10A. It is recommended to install a temperature control switch (45°C to 65°C normally closed type) in series with the heating circuit as a secondary protection.
6.6. Short Circuit Protection
The BMS includes standard short-circuit protection. You can set the short-circuit protection delay (µS) and recovery time (S) in the APP. If a short circuit is detected, the BMS will activate protection. Adjusting the delay can help prevent false triggers from high instantaneous currents during charger startup or load connection.
6.7. Intelligent Sleep
The intelligent sleep function allows the BMS to enter a low-power state when the charging and discharging current is less than 1A for 26 consecutive hours. This reduces the BMS's own energy consumption. To reactivate, press the button or connect a charger.
7. Troubleshooting
7.1. Emergency Switch
The BMS is equipped with an emergency switch. If issues like over-temperature, over-discharge, over-charge, or cell string drops occur during normal use, activating the emergency switch in the APP's BMS control page will enable charge and discharge for 30 minutes. This provides an emergency use period. Even if a single cell voltage reaches the automatic shutdown voltage, the protection board will continue to operate for this 30-minute cycle to prevent dangerous situations.
7.2. Common Issues and Solutions
- BMS not activating after installation: Ensure all balance cables are correctly connected, and P- and B- lines are secure. The BMS activates via charging (charger voltage 2V higher than battery voltage) or by pressing an optional activation button/display.
- Frequent overcurrent protection: Check the continuous charge/discharge current settings in the APP. Ensure they match your battery capacity and load. Consider increasing the overcurrent delay if false triggers occur due to high instantaneous currents.
- Battery imbalance issues: Verify the active balancing settings in the APP, including the trigger differential pressure. Ensure the balancing current (1A/2A) is sufficient for your battery pack.
- Temperature-related shutdowns: Check over-temperature and low-temperature protection settings in the APP. If operating in cold environments, consider enabling and properly configuring the optional heating function.
- Communication problems (Bluetooth/RS485/CAN): Ensure the mobile APP is installed correctly and Bluetooth is enabled on your device. For RS485/CAN, verify wiring and protocol settings in the APP or PC software.
8. User Tips
- Initial Setup: Always set the correct battery type (Li-ion, LiFePo4, LTO) and basic battery parameters (number of cells, capacity) in the mobile APP immediately after activation.
- Parameter Adjustment: For optimal performance and safety, carefully adjust protection values (overcharge, over-discharge, overcurrent, temperature, balance) in the APP to match your specific battery pack and application.
- Monitoring: Regularly check the battery status via the mobile APP or an external display to ensure healthy operation and identify potential issues early.
- Firmware Updates: Check the manufacturer's website or APP for any available firmware updates to ensure your BMS has the latest features and bug fixes.
9. Support and Documentation
For detailed technical support, troubleshooting, and the latest documentation, please refer to the official JIKONG resources. The full user manual in PDF format (Version 19.1.1) can be found at JIKONG Lithium Battery Active Balance Protection Board Maintenance Manual.
JIKONG Technology Co., Ltd. is committed to providing high-quality products and support. For any specific inquiries or customization needs, please consult customer service.
