Heltec BMS User Manual: 6S, 7S, 10S Li-Ion/LiFePO4 Battery Management System

1. Introduction

This manual provides essential information for the safe and effective use of your Heltec Battery Management System (BMS). The Heltec BMS is designed to protect and manage various lithium-ion battery configurations, including Li-Ion, LiFePO4, and LTO, for applications such as e-bikes and energy storage systems.

Key features include:

• Dual Current Options: Available in 30A and 60A models for flexible application.
• Comprehensive Protection: Offers overcharge, over-discharge, overcurrent, and short-circuit protection.
• Smart Balance Function: Passive balanced BMS ensures stable cell voltage across the battery pack.
• Wide Compatibility: Suitable for both power BMS and energy storage BMS scenarios.

2. Important Safety Notes

• Always ensure correct polarity and connection sequence when wiring the BMS to the battery pack. Incorrect wiring can cause damage to the BMS, battery, or connected devices.
• This product does not have a temperature control switch. If your application requires external temperature management, ensure it is in place.
• Handle with care to avoid physical damage.
• Keep the BMS away from moisture and extreme temperatures.
• Installation should be performed by individuals with appropriate electrical knowledge.

3. Specifications

3.1. Technical Parameters

3.2. General Specifications

4. Setup and Wiring

Proper wiring is critical for the safe and correct operation of the BMS. Follow the diagrams below carefully for your specific battery configuration (6S, 7S, or 10S).

1. Check Battery Series Sequence: Before connecting the BMS, ensure your battery cells are correctly arranged in series.
2. Connect Wiring: Connect the balance wires and main power wires strictly in accordance with the provided drawing.
3. Verify Connections: Double-check all connections for correctness and secure fit before inserting the balance board connector into the BMS.

4.1. Wiring Diagram for 6S 60A 3.7V BMS

4.2. Wiring Diagram for 7S 60A 3.7V BMS

4.3. Wiring Diagram for 10S 60A 3.7V BMS

Note: The 30A versions of the BMS follow similar wiring principles but are rated for lower continuous and overcurrent discharge. Always refer to the specific label on your BMS for exact current ratings and SKU.

5. Operation

Once correctly installed, the Heltec BMS operates automatically to manage and protect your battery pack. Its primary functions include:

• Overcharge Protection: Prevents individual cells from being charged beyond their safe voltage limit (4.25V).
• Over-discharge Protection: Stops discharge when cells reach their minimum safe voltage (2.8V) to prevent damage.
• Overcurrent Protection: Disconnects the load if the discharge current exceeds the specified maximum (100A for 30A models, 200A for 60A models).
• Short-Circuit Protection: Immediately cuts off power in the event of a short circuit to prevent damage and fire hazards.
• Passive Balancing: Continuously monitors cell voltages and dissipates excess energy from higher voltage cells to maintain overall pack balance, extending battery life and performance.

No user intervention is typically required for the core protective functions during normal operation.

6. Maintenance

The Heltec BMS is designed for low maintenance. To ensure its longevity and optimal performance:

• Keep Clean: Periodically inspect the BMS and connections for dust or debris. Clean gently with a dry, soft brush if necessary.
• Environmental Conditions: Ensure the BMS operates within its specified temperature range and in a dry environment to prevent corrosion or damage.
• Connection Integrity: Occasionally check that all wiring connections are secure and free from corrosion.

7. Troubleshooting

If you experience issues with your battery pack or BMS, consider the following basic troubleshooting steps:

• No Power Output:
  • Check all main power connections (Battery-, P-, Battery+, Charge/Discharge+) for secure contact and correct polarity.
  • Verify that the balance wires are correctly connected to each cell and to the BMS.
  • Measure individual cell voltages to ensure no cell is below the over-discharge protection threshold (2.8V). If a cell is too low, the BMS may have cut off power.
  • Check for any signs of short circuit or overcurrent events that might have triggered protection.
• Charging Issues:
  • Ensure the charger is functioning correctly and connected to the appropriate charge/discharge port.
  • Check for overcharge protection activation if cells are already at or near 4.25V.
• Unbalanced Cells:
  • While the BMS has passive balancing, significant cell imbalance might indicate a faulty cell or prolonged storage. Allow the BMS time to balance during charging.

If problems persist after basic checks, it is recommended to consult with a qualified technician or contact Heltec customer support.

8. User Tips

Based on general best practices for BMS usage:

• Initial Charge: After installation, perform a full charge cycle to allow the BMS to balance the cells effectively.
• Monitor Performance: If possible, periodically monitor individual cell voltages to ensure the battery pack remains balanced over time.
• Ventilation: Ensure adequate ventilation around the battery pack and BMS, especially during high current draw or charging, to prevent overheating.
• Correct Sizing: Always choose a BMS with current ratings appropriate for your battery pack and application to avoid triggering protection prematurely or damaging the BMS.

9. Warranty and Support

For technical support, warranty claims, or further assistance, please contact the HeltecTools Store directly.

• Store Name: HeltecTools Store
• Store Homepage: HeltecTools Store on AliExpress
• Product Complaint: If you need to report an issue with the product, you can use the official complaint channel: Report this item

Please retain your purchase receipt for warranty purposes.