Product Description:
The BAK N21700CG-50 is a premium-grade 21700 lithium-ion battery cell engineered for high-capacity energy storage and reliable power delivery. With a true 5000mAh (4900mAh typical) capacity and a stable 3.6V nominal voltage, this cell delivers exceptional energy density, making it the ideal core for high-capacity portable power stations, solar energy storage systems, and DIY battery pack assemblies.
Manufactured by BAK, a leading global lithium battery manufacturer, this cell features ultra-low internal resistance (≤25mΩ) and proven performance under sustained loads. According to the official specification sheet, it supports a 3C (14.7A) maximum discharge current for high-power bursts, and maintains a wide operating temperature range for reliable performance in various environments. With two cells included, you have the flexibility to power a single device, rotate batteries for continuous operation, or begin building your custom battery system.
Key Features:
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BAK N21700CG-50 High-Capacity Cell: Premium-grade 21700 Li-ion battery from the trusted brand BAK.
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5000mAh (4900mAh Typ.) True Capacity: Provides massive energy for extended runtimes.
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3.6V Nominal Voltage: Stable voltage output for consistent device performance.
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14.7A (3C) Max Discharge Current: Delivers high burst power for demanding applications (Note: For cycle life, standard 0.2C discharge is recommended).
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Ultra-Low Internal Resistance (≤25mΩ): Ensures minimal heat generation and maximum energy efficiency.
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Wide Operating Temperature: Supports charging from 0°C to 45°C and discharging from -20°C to 60°C.
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Professional Grade Quality: Manufactured by BAK with strict quality control and rigorous testing.
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Versatile Applications: Perfect for portable power stations, solar storage, and DIY battery projects.
Product Parameters (Based on the Provided Spec Sheet):
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Brand: BAK
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Model: N21700CG-50
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Size: 21700
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Typical Capacity: 4900mAh / 5000mAh (Typical)
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Nominal Voltage: 3.6V
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Charging Limited Voltage: 4.20V
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Standard Charging Current: 0.5C (2450mA)
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Max Charging Current: 1C (4900mA)
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Standard Discharge Current: 0.2C (980mA)
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Max Discharge Current: 3C (14.7A) – Not for cycle life; for burst usage only.
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Discharge Cut-off Voltage: 2.50V (Standard) / 2.00V (Absolute)
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Internal Resistance: ≤25mΩ (AC Impedance, 1000Hz)
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Weight: ≤70g (Measured: ~68.2g)
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Operating Temp - Charging: 0°C to 45°C
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Operating Temp - Discharging: -20°C to 60°C
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Storage Temp: -20°C to 45°C (1-year recommend)
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Dimensions: 21.40mm (Max Diameter) x 70.75mm (Max Height)
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Pack Quantity: 2-Pack
Applications:
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High-Capacity Portable Power Stations: The ideal core cell for building large-capacity outdoor camping power stations and emergency backup power.
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Solar Energy Storage Systems: Reliable, high-capacity energy storage for off-grid solar setups and home backup systems.
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High-Performance LED Flashlights: Powers high-lumen searchlights and tactical flashlights for extended outdoor operations.
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DIY Battery Pack Assemblies: Perfect for building custom 12V/24V battery packs for various DIY projects.
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Electric Vehicle Conversions: Delivers long-lasting, stable power for retrofitting e-bikes and electric scooters.
Frequently Asked Questions (FAQ):
Q1: What is the discharge current of this battery?
A1: According to the official spec sheet, this cell supports a 3C (14.7A) maximum discharge current. However, please note that the spec sheet explicitly states "3C max discharge, not for cycle life." For daily use and maximizing cycle life, we recommend using a standard 0.2C (980mA) discharge.
Q2: What is the typical capacity of this battery?
A2: The BAK N21700CG-50 has a typical capacity of 4900mAh, with a maximum rated capacity of 5000mAh. This provides massive energy for extended runtimes in high-drain applications.
Q3: What kind of charger should I use for this battery?
A3: You must use a charger specifically designed for 3.6V/3.7V Li-ion batteries with a 4.2V cut-off voltage. We recommend using a high-quality smart charger with over-charge protection.
Q4: Is this battery safe for use in high temperatures?
A4: Yes. The spec sheet indicates a wide operating temperature range: discharging from -20°C to 60°C, and charging from 0°C to 45°C.
Q5: Can I use this battery to build a 12V battery pack?
A5: Yes. For a standard 12V system, you would connect 3 cells in series (3S) to achieve 10.8V nominal (3.6V x 3). Always use a BMS (Battery Management System) when building custom packs to ensure safety and balance.
