How to Use 21700 LI: Examples, Pinouts, and Specs

The 21700 LI is a cylindrical lithium-ion rechargeable battery cell manufactured by Molicel. It is known for its large capacity and high current output, making it an ideal power source for high-drain electronic devices such as electric vehicles, power tools, and portable electronics. The 21700 designation refers to the cell's dimensions: approximately 21mm in diameter and 70mm in length.

• Electric vehicles (EVs)
• Power tools
• Portable electronics
• Energy storage systems
• High-performance flashlights
• Uninterruptible power supplies (UPS)

Below are the key technical details for the Molicel 21700 LI battery cell:

The 21700 LI battery cell does not have a pin configuration as it is a cylindrical cell with a positive and negative terminal.

1. Battery Holder: Use a 21700-compatible battery holder or a custom battery pack to securely hold the battery cells.
2. Proper Orientation: Ensure the positive and negative terminals are correctly aligned with the corresponding connections in your device or battery management system (BMS).
3. Voltage and Current Regulation: Use a BMS to monitor and regulate the voltage and current during charging and discharging to prevent overcharging, deep discharging, and short-circuiting.
4. Temperature Monitoring: Ensure the battery operates within the specified temperature range.

• Charging: Use a charger specifically designed for lithium-ion batteries. Do not exceed the maximum charging voltage.
• Discharging: Do not discharge the battery below its minimum voltage to avoid damaging the cell.
• Storage: Store the battery at a 40-60% charge level in a cool, dry place when not in use.
• Safety: Do not puncture, crush, or expose the battery to water or fire. Always follow safety guidelines provided by the manufacturer.

• Battery Won't Charge: Ensure the charger is functioning and compatible. Check the battery terminals for corrosion or damage.
• Reduced Capacity: If the battery does not hold a charge as expected, it may be nearing the end of its lifecycle or may have been subjected to improper use or storage conditions.
• Overheating: If the battery overheats during use or charging, immediately stop using it and allow it to cool down. Check for short circuits or overloading.

• Charging Issues: Verify the charger's output voltage and current. Inspect the battery contacts and clean them if necessary.
• Capacity Issues: Perform a few charge-discharge cycles to recalibrate the battery. If the issue persists, consider replacing the cell.
• Overheating: Ensure adequate ventilation and check for any external factors that may contribute to overheating. Consult the manufacturer if the problem continues.

Q: Can I charge the 21700 LI battery with a standard lithium-ion charger? A: Yes, as long as the charger is compatible with the voltage and current requirements of the 21700 LI battery.

Q: How do I dispose of a 21700 LI battery? A: Do not dispose of lithium-ion batteries in household waste. Recycle them according to local regulations, often at designated battery recycling centers.

Q: Is it safe to carry 21700 LI batteries on a plane? A: There are restrictions on carrying lithium-ion batteries on aircraft. Check with the airline and follow the Transportation Security Administration (TSA) guidelines.

Q: Can I use the 21700 LI battery in series or parallel configurations? A: Yes, but it is crucial to use a BMS to ensure balanced charging and discharging, and to protect against potential hazards.

Q: How long does a 21700 LI battery last? A: The lifespan depends on usage patterns and care. Typically, a 21700 LI battery can last for over 500 charge cycles before noticeable capacity degradation occurs.

For further assistance, please refer to the manufacturer's official documentation or contact Molicel's customer support.