GEB 21700 3.7V 4000mAh Cylindrical Li-ion Battery Cell (21×70mm)
Grade-A GEB 21700 3.7V 4000mAh Li-ion Battery Cell for Electric Bicycles & Scooters (3.7V, 4000mAh) cylindrical battery with Ø 21.2 ± 0.2 mm × H 70.5 ± 0.3 mm dimensions, low IR, and UN38.3 documentation for Electric bicycles, power tools, electric scooters, medical equipment, custom battery pack modules.
B2B Engineering Review & Pricing
Direct manufacturer supply, custom BMS telemetry, and CAD fit validation for OEM/ODM projects.
Product Details
The GEB 21700 3.7V 4000mAh Cylindrical Li-ion Battery Cell is an automotive-grade cylindrical power cell engineered for electric bicycles (E-bikes), electric scooters, and high-capacity portable power stations. Featuring ternary NCM chemistry in a standard 21×70mm format weighing ~69g, it delivers 3.7V nominal output, 4000mAh rated capacity (14.8Wh energy), continuous discharge rates up to 2.5C (10A continuous), and low AC internal resistance (≤18 mΩ) for efficient thermal management in multi-cell 10S/13S/14S battery packs.
Product Overview
The GEB 21700 3.7V 4000mAh Cylindrical Li-ion Battery Cell (21×70mm) is an industrial-grade cylindrical cell manufactured to strict electrochemical tolerances for high-reliability mobility and power storage. Featuring a 3.7V nominal voltage and 4000mAh rated capacity (14.8Wh total energy), this cell incorporates a pressure-relief safety vent, precision steel can packaging, and ultra-low internal resistance. With physical dimensions of Ø 21.2 ± 0.2 mm × H 70.5 ± 0.3 mm; unit weight is confirmed for the selected configuration. 69g ± 2g, it is engineered for electric bicycles (E-bikes), e-scooters, commuter EV powertrains, and portable power stations. Before module assembly, verify spot welding pure nickel tab thickness, cell spacing holders, and charger cutoff calibration.
Product Specifications
| Feature / Attribute | Technical Specification |
|---|---|
| Battery Chemistry | Ternary Lithium Nickel Manganese Cobalt (INR21700 NCM) |
| Nominal Voltage & Capacity | 3.7V / 4000mAh (14.8Wh total energy) |
| Physical Dimensions & Weight | Ø 21.2 ± 0.2 mm × H 70.5 ± 0.3 mm / Approx. 69g ± 2g |
| Continuous Discharge Rating | 1.0C–2.5C (4A–10A continuous discharge) |
| Peak Pulse Discharge | 3.0C–4.0C (12A–16A pulse ≤ 5s) |
| Target Applications | Electric bicycles (E-bikes), e-scooters, light commuter EV powertrains, portable power stations |
| Terminal Form Factor | Flat Top / Button Top / Pre-welded Solder Tabs |
| Service Life / Endurance | ≥ 500–1,000 cycles (@ 80% DoD, 25°C, 0.5C/0.5C) |
Technical Specifications
| Parameter | Value | Test Conditions & Engineering Tolerances |
|---|---|---|
| Nominal Operating Voltage | 3.7V | Standard measurement @ 25°C, 0.2C rate |
| Upper Voltage / Cutoff | 4.20V ± 0.02V (CC/CV mode) | Regulation tolerance ±0.02V |
| Discharge Lower Cutoff | 2.75V – 3.00V ± 0.03V | Safety lower voltage threshold |
| Standard Charge Current | 0.5C (2.0A) | Max Fast Charge: 1.0C (4.0A) | CC/CV charge mode, 0.02C termination |
| Internal AC Resistance (1kHz) | ≤ 18–25 mΩ | 1kHz AC test @ 25°C fully charged state |
| Cell Consistency Screening | ΔV ≤ 3mV | ΔR ≤ 1.5mΩ | Pre-assembly automated barcode classification SOP |
| Operating Temperature Range | Charge: 0~45°C | Discharge: -20~60°C | Ambient environmental test qualification |
Equipment Compatibility & Engineering Fit Check
Before deploying GEB 21700 3.7V 4000mAh Cylindrical Li-ion Battery Cell (21×70mm), verify these verified electrical and mechanical boundary requirements:
Operational Boundary Conditions
✔ Recommended Fit & Use Cases:
- Electronic devices and OEM packs matched with 3.7V / 4Ah power curves.
- Commercial designs requiring high volumetric energy density and predictable discharge curves.
- Projects requiring batch consistency with automated barcode impedance sorting.
⚠ Operational Constraints & Limits:
- Do not discharge below minimum cutoff voltage or charge beyond 4.2V.
- Maintain operational surface temperature within -20°C to +60°C discharge (0°C to +45°C charge).
- Ensure connector polarity and pin assignment match system schematics prior to initial power-up.
First-Party Manufacturing SOP & Export Compliance
Technical Whitepapers & Engineering Guides
High-Performance Cylindrical Batteries: 16 Years of B2B Manufacturing
Technical breakdown of automated cell sorting, delta IR matching, laser welding busbars, and cycle aging protocols.
Industrial Cylindrical Batteries: QC, Aging and Test Standards
Key factory inspection criteria for cylindrical packs, thermal management, vibration testing, and BMS protection thresholds.
Cylindrical Battery Sourcing: Capacity and QC Verification Guide
How hardware engineers evaluate true C-rate capability, temperature rise curves, and Grade-A barcode traceability.
