1. Introduction
This manual provides essential information for the safe and effective use of the AEDIKO HW-375 3S 20A Li-ion Lithium Battery BMS (Battery Management System) Protection Board. This module is designed to protect 3-series (3S) 18650 Li-ion battery packs, ensuring their longevity and safe operation by managing charging and discharging processes.
2. Product Overview
The AEDIKO HW-375 is a compact and reliable protection board for 3S Li-ion battery packs, typically used for 11.1V, 12V, or 12.6V applications. It integrates multiple protection features to safeguard your battery cells.
Key Features:
- Over-Discharge Protection: Prevents battery cells from being discharged below a safe voltage level.
- Over-Current Protection: Limits the current drawn from the battery to prevent damage.
- Short Circuit Protection: Automatically cuts off power in case of a short circuit.
- High Accuracy Voltage Detection: Ensures precise monitoring of cell voltages.
Image 2.1: Multiple AEDIKO HW-375 3S 20A BMS protection boards. Each board is green, rectangular, and features various electronic components including MOSFETs and resistors.
Image 2.2: A detailed view of the front side of the HW-375 BMS board. Labels for 'OV' (Over-Voltage), '4.2V', '8.4V', '12.6V', '20A', 'FD', 'CD', and 'HW-375' are visible, indicating connection points and specifications.
Image 2.3: The back side of the HW-375 BMS board. Printed text in Chinese translates to: "12.6V Lithium Battery Protection Board REV 2.3. Applicable to motors/drills. Short circuit prohibited." This indicates the board's voltage rating, intended applications, and a critical safety warning.
3. Safety Information
Please read and understand all safety warnings before installing or operating the BMS module. Failure to follow these instructions may result in fire, electric shock, or other injuries.
- Voltage Compatibility: This BMS is designed for 3S (three series) Li-ion battery packs with a nominal voltage of 11.1V/12V and a full charge voltage of 12.6V. Do not use with other battery chemistries or cell configurations.
- Current Limits: The continuous discharge current limit is 20A. Exceeding this limit, especially without adequate heat dissipation, can damage the module and batteries.
- Short Circuit Prevention: Always ensure correct wiring and avoid any possibility of short circuits during installation and operation. The board includes short circuit protection, but intentional shorting can still cause damage.
- Polarity: Double-check all positive and negative connections before applying power. Incorrect polarity will damage the BMS and potentially the batteries.
- Professional Installation: If you are unfamiliar with electronics or battery pack assembly, seek assistance from a qualified professional.
- Heat Dissipation: For continuous high current applications, ensure sufficient airflow and heat dissipation for the BMS module.
4. Setup and Installation
Proper wiring is critical for the correct function and safety of the BMS. Refer to the wiring diagram below and follow the steps carefully.
Wiring Diagram:
Image 4.1: Wiring diagram illustrating the connection of three 18650 Li-ion cells in series to the AEDIKO HW-375 BMS board. The diagram shows connections for 'OV' (0V/B-), '4.2V' (B1), '8.4V' (B2), and '12.6V' (B+), as well as output terminals for 'Charger' and 'Load'.
Installation Steps:
- Prepare Batteries: Ensure your three 18650 Li-ion cells are of the same type, capacity, and charge level for optimal performance. Connect them in series.
- Connect B- (0V): Connect the negative terminal of the first battery cell (B-) to the 'OV' pad on the BMS board. This is the common negative for the entire pack.
- Connect B1 (4.2V): Connect the positive terminal of the first cell (which is also the negative of the second cell) to the '4.2V' pad on the BMS board.
- Connect B2 (8.4V): Connect the positive terminal of the second cell (which is also the negative of the third cell) to the '8.4V' pad on the BMS board.
- Connect B+ (12.6V): Connect the positive terminal of the third battery cell (B+) to the '12.6V' pad on the BMS board. This is the common positive for the entire pack.
- Connect Charger/Load: The main output terminals for charging and discharging are labeled 'Charger' and 'Load' on the diagram. Connect your charger's positive output and your device's positive input to the 'Charger/Load' positive terminal. Connect the negative of both the charger and load to the 'OV' (B-) terminal of the BMS.
- Verify Connections: Before applying power, carefully inspect all connections for correct polarity and secure contact. Loose connections can cause arcing or damage.
5. Operating Instructions
The AEDIKO HW-375 BMS operates automatically once correctly installed. It continuously monitors the battery pack's voltage and current to provide protection.
- Charging: Connect a compatible 12.6V Li-ion charger to the designated terminals. The BMS will manage the charging process, preventing overcharge by cutting off current when the pack reaches 12.6V (4.2V per cell).
- Discharging: Connect your load (e.g., motor, LED light) to the designated terminals. The BMS will allow current draw up to 20A. If the battery voltage drops below the over-discharge threshold (approximately 7.6V for the pack, or 2.53V per cell), the BMS will cut off the output to protect the cells from damage.
- Over-Current/Short Circuit: In the event of an excessive current draw or a short circuit, the BMS will instantly cut off the output to prevent damage to the battery pack and the module itself. The output will typically resume once the fault condition is removed.
6. Maintenance
The AEDIKO HW-375 BMS is a low-maintenance component. Follow these general guidelines to ensure its longevity:
- Keep Dry: Protect the module from moisture and liquids.
- Cleanliness: Keep the board free from dust and debris. Use a soft, dry brush if cleaning is necessary.
- Temperature: Operate the module within its specified temperature range. Avoid extreme heat or cold.
- Physical Damage: Avoid dropping or subjecting the board to physical shock.
7. Troubleshooting
If you encounter issues with your BMS module, consider the following troubleshooting steps:
| Problem | Possible Cause | Solution |
|---|---|---|
| No output power | Incorrect wiring, battery voltage too low (over-discharged), short circuit, over-current protection triggered. | Check all wiring connections. Measure individual cell voltages; if below 2.5V, cells may be damaged. Remove load to check for short circuit. Reduce load current. |
| Battery not charging | Charger not connected correctly, charger faulty, battery pack already fully charged (BMS cut-off). | Verify charger connections and functionality. Check if battery pack voltage is already at 12.6V. |
| BMS gets hot | Excessive discharge current, poor heat dissipation. | Reduce load current. Ensure adequate airflow around the BMS. Consider adding a heatsink if operating near maximum current continuously. |
| Output cuts off frequently | Load current exceeds 20A, battery voltage drops rapidly under load (weak cells), intermittent short circuit. | Measure peak load current. Test battery cells individually for capacity and internal resistance. Inspect wiring for intermittent shorts. |
8. Specifications
| Parameter | Value |
|---|---|
| Model | HW-375 |
| Battery Type | 3S Li-ion (Lithium-ion) |
| Charging Voltage | 12.6V |
| Maximum Output Current | 20A (Continuous) |
| Quiescent Current | <30uA |
| Over-Discharge Detection Voltage | Approx. 2.53V per cell (7.6V for 3S pack) |
| Over-Charge Detection Voltage | Approx. 4.2V per cell (12.6V for 3S pack) |
| Short Circuit Protection | Yes |
| Over-Current Protection | Yes |
| Dimensions (approx.) | 4.02 x 3.07 x 0.47 inches (Package) |
| Weight (approx.) | 1.06 ounces |
Note: Specifications are subject to change without prior notice. Always refer to the product packaging or manufacturer's website for the most current information.
9. Warranty and Support
For warranty information and technical support, please refer to the seller or the official AEDIKO website. Keep your proof of purchase for any warranty claims.
If you have questions regarding the installation or operation of your AEDIKO HW-375 BMS module, please contact the retailer from whom you purchased the product.