FEB 21700 Battery Cell – 6500mAh 13A Ultra High Capacity Energy Cell

FEB 21700G 21700 6500mAh 13A Max Lithium-Ion Battery Cell

The FEB 21700G is a high-capacity 21700 lithium-ion battery cell rated at 6500mAh with a temperature-dependent maximum discharge rating up to 13A.

The FEB 21700G 6500mAh cell is designed for battery packs where high capacity, long runtime, and energy density are more important than extreme discharge current. With a 3.6V nominal voltage and 6.5Ah rated capacity, each cell provides approximately 23.4Wh of energy in a 21700 cylindrical format.

This is a high-capacity energy cell, not a high-discharge power cell. The manufacturer lists a maximum discharge current up to 13A, but that rating is temperature dependent and only applies within the specified cell temperature range. For long-term reliability, pack design, cooling, current sharing, busbar design, wire gauge, and BMS settings all matter.

Key Features

• 6500mAh nominal capacity for extended runtime
• 6350mAh minimum capacity
• 3.6V nominal voltage and 4.20V full charge voltage
• Standard discharge current of 6.5A
• Manufacturer maximum discharge rating up to 13A from 0°C to 35°C
• 316Wh/kg listed energy density
• Best suited for energy-focused and long-runtime battery packs

Specifications

Recommended Use

The FEB 21700G is recommended for high-capacity battery packs where runtime and energy storage are the main priorities. For conservative long-term use, design around the standard 1C discharge current of 6.5A per cell or lower. The 13A rating should be treated as a temperature-limited maximum, not a universal continuous design target.

Real-World Performance Notes

This cell can deliver strong runtime because of its 6500mAh capacity, but it should not be treated like a high-power 21700 cell. The datasheet shows discharge efficiency of 100% at 0.2C, ≥95% at 0.5C, ≥93% at 1C, and ≥90% at 2C under room-temperature test conditions.

For real battery packs, performance depends on temperature, cooling, pack layout, nickel or copper busbar design, wire gauge, BMS settings, and how evenly the current is shared between parallel cells. If your application needs high current, increase the parallel count or choose a dedicated high-discharge cell.

Applications

• High-capacity DIY battery packs
• Solar and backup energy storage systems
• Portable power stations
• Long-runtime low to moderate current devices
• Long-range e-bike packs with proper parallel cell count

Important Notes

• The 13A rating is temperature dependent and applies only within the datasheet's specified conditions.
• Do not advertise or use this cell as a 65A cell.
• Do not charge above 4.20V per cell.
• Do not discharge below 2.50V per cell.
• For long-term storage, keep cells at 10% to 35% state of charge.
• Real-world performance depends on temperature, airflow, pack design, busbar material, wire gauge, BMS, and application.
• Cells should be resistance welded or laser welded. Do not solder directly to battery terminals.

FAQ

Is the FEB 21700G a high-discharge cell?

No. The FEB 21700G is a high-capacity energy cell. It is rated up to 13A under the correct temperature range, but it is not intended to replace a true high-discharge power cell.

Can this cell be used for e-bike battery packs?

Yes, if the pack has enough cells in parallel to keep current per cell within a reasonable range. It is better suited for long-range, moderate-current e-bike packs than aggressive high-power builds.

Safety Warning for Lithium-Ion Battery Usage

Customers should have a clear understanding of lithium-ion battery handling and safety before making a purchase. Lithium-ion batteries are highly sensitive and may pose fire, burn, or explosion risks if improperly handled. Always charge batteries on fire-resistant surfaces, and never leave them charging unattended.

By purchasing, you assume full responsibility for any injury, damage, or loss arising from the incorrect use or handling of lithium-ion batteries or chargers. Compatibility with specific devices is not guaranteed. Only charge using a smart charger designed specifically for this battery type, and do not mix old or used batteries with new ones.

Important Usage Guidelines

• Not for Use in E-Cigarettes or Similar Devices: Lithium-ion batteries present a serious risk of injury, property damage, or even death if improperly used.
• Risk of Fire and Explosion: Misuse can cause batteries to ignite, explode, or release harmful gases.
• Always Use in a Protected Pack: Ensure batteries are used within intended specifications and supported by appropriate circuitry.
• Proper Storage and Handling: Store batteries in protective cases, away from metal items to prevent short circuits.
• Inspection Prior to Use: Do not use batteries with damaged wrappers, torn insulators, or visible damage.
• Follow Manufacturer's Charging Specifications: Avoid overcharging or over-discharging, and never alter, dismantle, puncture, crush, or burn.
• Heat and Water Precautions: Do not expose batteries to high temperatures or any liquids.
• Assembly Guidelines: Batteries should only be spot welded; do not solder directly onto battery terminals.

Users are expected to have battery-handling knowledge before purchasing. By using these batteries, you acknowledge that usage is solely at your own risk, and you take full responsibility for any resulting consequences.

For Resellers

Please ensure all safety information is passed along to end users to promote safe handling and proper use.