HX-2s-D01 2S 7.4V 8A Lithium Battery Charger Protection Board User Manual

1. Introduction

This manual provides detailed instructions for the HX-2s-D01 2S 7.4V 8A Lithium Battery Charger Protection Board. This board is designed to protect 2-series (2S) lithium-ion batteries, such as 18650 cells, from overcharge, over-discharge, over-current, and short-circuit conditions, ensuring safe and reliable operation of your battery pack.

Figure 1: Front view of the HX-2s-D01 protection board.

2. Specifications

The following table outlines the key technical specifications of the HX-2s-D01 protection board:

Figure 2: Dimensions of the HX-2s-D01 protection board (41mm x 16mm).

3. Setup and Connection

Proper connection is crucial for the safe and effective operation of the protection board. Please follow the instructions and diagrams carefully.

3.1. Connection Instructions

1. B+ (Battery Positive): Connect this terminal to the positive (+) anode of your battery pack.
2. B- (Battery Negative): Connect this terminal to the negative (-) cathode of your battery pack.
3. BM (Balance Middle): Connect this terminal to the junction point between Battery 1 and Battery 2 in your 2S series battery pack. This is for cell balancing.
4. P+ (Output Positive): This is the positive terminal for both charging input and load output. Connect your charger's positive output and your load's positive input here.
5. P- (Output Negative): This is the negative terminal for both charging input and load output. Connect your charger's negative output and your load's negative input here.

3.2. Wiring Diagram

Refer to the following diagrams for visual guidance on connecting your 2S lithium battery pack to the HX-2s-D01 protection board.

Figure 3: Standard wiring diagram for 2S battery connection.

Figure 4: Alternative wiring diagram showing battery connections.

4. Operating Principles

The HX-2s-D01 protection board operates automatically once correctly installed. It continuously monitors the voltage of each cell in the 2S battery pack, as well as the overall current flow, to provide the following protections:

• Overcharge Protection: Prevents individual cells from being charged beyond their safe voltage limit (4.25V ~ 4.35V). Once a cell reaches this limit, charging is halted.
• Over-discharge Protection: Prevents individual cells from being discharged below their safe voltage limit (2.5V ~ 3.0V). If a cell drops below this threshold, the load is disconnected to prevent damage.
• Over-current Protection: Limits the discharge current to a maximum of 8A (10A instantaneous peak) to protect the batteries and the board from excessive current draw.
• Short-circuit Protection: Immediately disconnects the load in the event of a short circuit to prevent damage and potential hazards. The board requires a charge input to reset after a short-circuit event.

5. Maintenance

The HX-2s-D01 protection board is a low-maintenance electronic component. To ensure its longevity and optimal performance:

• Keep Clean: Ensure the board is free from dust, dirt, and moisture. Use a soft, dry brush or compressed air for cleaning if necessary.
• Avoid Physical Damage: Protect the board from impacts, bending, or excessive pressure.
• Temperature Control: Operate and store the board within the specified temperature ranges (-40°C to +50°C for operation, -40°C to +80°C for storage) to prevent component degradation.
• Inspect Connections: Periodically check all wiring connections to ensure they are secure and free from corrosion. Loose connections can lead to poor performance or damage.

6. Troubleshooting

If you encounter issues with your HX-2s-D01 protection board, consider the following common problems and solutions:

• No Output Voltage:
  • Check if the battery pack is fully charged. The board might have entered over-discharge protection.
  • Verify all connections (B+, B-, BM, P+, P-).
  • If a short circuit occurred, connect a charger to the P+ and P- terminals to reset the protection.
• Battery Not Charging:
  • Ensure the charger voltage is within the specified range (8.4V - 9V).
  • Check for overcharge protection activation. If cells are already at max voltage, charging will stop.
  • Inspect charger connections to P+ and P-.
• Overheating:
  • Reduce the load current. The board might be operating near or above its maximum working current (8A).
  • Ensure adequate ventilation around the board.
• Unbalanced Cell Voltages:
  • While this board offers basic protection, it may not include active balancing. For critical applications, consider external balancing solutions or ensure cells are matched.
  • Verify the BM connection is correctly made to the cell junction.

7. User Tips

• Always use high-quality lithium-ion batteries (e.g., 18650 cells) that are matched in capacity and internal resistance for optimal performance and safety in a 2S pack.
• When soldering, apply heat quickly and avoid prolonged contact with the terminals to prevent damage to the board's components.
• Before connecting the battery pack to the protection board, ensure that the individual cell voltages are relatively close to each other to minimize initial balancing stress.
• For applications requiring continuous high current, ensure your wiring is sufficiently thick to handle the current without excessive voltage drop or heating.
• Test the protection functions (e.g., short circuit) with a controlled, low-power load first to confirm proper operation before deploying in a critical application.

8. Warranty and Support

This product is typically covered by a standard manufacturer's warranty against defects in materials and workmanship. For specific warranty details, technical support, or assistance with product issues, please contact your retailer or the manufacturer directly. Keep your purchase receipt as proof of purchase.