Tewaycell LiFePO4 Battery Cell User Manual

1. Introduction

This manual provides essential information regarding the type, size, performance, technical characteristics, warnings, and cautions for the Tewaycell 4LH3L7 3.2V 1008Wh prismatic LiFePO4 rechargeable cell. Adherence to these guidelines is crucial for safe and efficient operation.

For a detailed specification document, please refer to the official PDF: Item guides & documents (PDF).

2. Safety Warnings and Precautions

⚠️ WARNING: This product contains Lithium carbonate, a chemical known to the State of California to cause developmental toxicity. For more information go to www.P65Warnings.ca.gov.

⚠️ DISCLAIMER: Please mind potential fire risk and strictly follow the instruction manual for charging and storage. For disposal, please check your local authority's website for more information and dispose of the lithium-ion battery safely in accordance with the applicable legal requirements.

General Safety Guidelines:

• Do not immerse the battery in water or seawater. Store in a cool and dry environment when not in use.
• Do not use or leave the cell near a heat source such as fire or a heater.
• Do not reverse the positive and negative terminals.
• Do not disassemble or modify the cell.
• Do not use the cell if it has conspicuous damage or deformation.
• Do not connect the cell directly to an electrical outlet.
• Do not discard the cell in fire or a heater.
• Do not short circuit, over-charge, or over-discharge the cell.
• Do not transport and store the cell together with metal objects such as necklaces or hairpins.
• Do not mix this lithium-ion battery with other types or models of lithium batteries.
• Keep the battery away from children.
• Do not strike, throw, or trample the cell.
• Do not pierce the battery with sharp objects (e.g., nails, knives, pens, electric drills).
• Do not use damaged cells.
• Battery pack design and packing must prevent injury to batteries.
• Battery replacement should only be performed by the cell supplier or device supplier, never by the user.
• Be aware that discharged batteries may cause fire; tape the terminals to insulate them.
• Avoid using the battery in areas with strong electrostatic or magnetic fields, as this may damage safety devices.
• Do not directly solder the battery.
• When disposing of secondary cells, keep cells of different electrochemical systems separate.
• Do not use or leave the cell in very high-temperature conditions (e.g., strong direct sunlight, inside a hot vehicle).

3. Setup and Assembly

The battery cells are typically supplied with busbars and M6 bolts for connection. For example, if you purchase 4 cells, you will receive 4 sets of busbars and bolts.

Assembly Steps:

1. Ensure all cells are at a similar State of Charge (SOC) before assembly.
2. Carefully align the positive and negative terminals of the cells for series or parallel connection as required for your battery pack configuration.
3. Place the busbars over the terminals, ensuring proper contact.
4. Secure the busbars with the provided M6 bolts, tightening them to the recommended torque to ensure a stable and low-resistance connection.
5. Pay close attention to insulation to prevent short circuits during and after assembly.
6. Verify the orientation of positive and negative terminals before making final connections.

Image: Tewaycell LiFePO4 battery cells with busbars and bolts for assembly.

Image: Detailed view of a 315Ah LiFePO4 cell, showing terminals, explosion-proof valve, and QR code.

4. Operating Instructions

Charging:

• Standard Charge Method: At 25±2°C, charge the cell to 3.65V with a constant current of 0.5C (157.5A). Continue charging with a constant voltage of 3.65V until the charging current drops to 0.05C.
• Charging Voltage: 3.65V
• Maximum Continuous Charge Current: 157.5A (0.5C)
• Charge Temperature Range: 0°C to 60°C. If the cell temperature exceeds this range, charging should be stopped.

Discharging:

• Standard Discharge Method: At 25±2°C, discharge the cell to 2.5V with a constant current of 0.5C (157.5A).
• Rapid Discharge Method: At 25±2°C, discharge the cell to 2.5V with a constant current of 1C (315A).
• Discharge End Voltage: 2.5V
• Maximum Continuous Discharge Current: 315A (1C)
• Maximum Peak Discharge Current: 630A (for 30 seconds)
• Discharge Temperature Range: -30°C to 60°C.

Charging and Discharging Current Limits at Different Temperatures:

Image: Internal resistance and voltage measurement of a LiFePO4 battery cell.

5. Maintenance and Storage

Storage:

• When not in use for a long time, the battery should be stored in a cool and dry place (<35°C).
• Maintain a State of Charge (SOC) between 30% and 50% for long-term storage.
• For long-term storage (more than 3 months), it is recommended to charge and discharge the cell once every 3 to 6 months to maintain its health. The SOC should not fall below 5%.
• Avoid direct sunlight or heat sources during storage.
• Recommended storage temperature: -10°C to 25°C with 85% RH Max.
• Maximum storage temperature range: -30°C to 60°C.

Cleaning:

• If the cell terminals become dirty, clean them with a dry cloth before use to ensure good electrical contact.

Image: LiFePO4 battery cells packaged in foam for protection during storage or transport.

6. Troubleshooting

Electrolyte Leakage:

• If the cell leaks and electrolyte gets into your eyes, do NOT rub your eyes. Immediately rinse your eyes thoroughly with clean running water for at least 15 minutes and seek immediate medical attention. Failure to do so may result in eye injury.

Abnormal Conditions:

• If the cell emits an odor, generates heat, becomes discolored or deformed, or exhibits any other abnormal behavior during usage, recharging, or storage, immediately remove it from the device or charger and discontinue use.

7. Specifications

8. Warranty and Support

Warranty:

The product comes with a 5-year warranty. The warranty period is determined by the business contract. However, AESC will not replace cells free of charge if problems arise due to customer abuse, misuse, or handling outside of the specified instructions, or if issues occur from matching with incompatible electric circuits, battery packs, or chargers. AESC is also exempt from warranty for defective cells during assembly after acceptance.

Support:

If you require applications or operating conditions different from those described in this document, please contact Tewaycell (AESC) in advance.

Image: Certifications for Tewaycell batteries.

9. User Tips

• Initial Use: Cells are shipped with a State of Charge (SOC) between 20% and 40%. The remaining capacity before charging may vary depending on storage time and conditions. It is recommended to fully charge the cells before first use.
• Battery Management System (BMS): For optimal performance and safety, especially when building battery packs (e.g., 12V, 24V, 48V), consider using a suitable Battery Management System (BMS) to monitor and balance the cells. This helps prevent overcharge, over-discharge, and ensures cell longevity.
• Cell Balancing: Regular balancing of cells is crucial for maintaining pack health and maximizing cycle life. The manufacturer performs safety tests, cycle life tests, and balances voltage and internal resistance on all batteries before shipment.
• Connection Hardware: Ensure all busbars and bolts are properly installed and tightened to prevent loose connections, which can lead to increased resistance and heat.