INR21700-RS50 5000mAh 70A High-Drain Tabless Lithium-ion Cell for Drone Power Tools
Product Overview
The INR21700-RS50 is a cutting-edge, high-drain cylindrical lithium-ion cell manufactured by Reliance (Jiangsu Reliance Energy Tech. Co., Ltd.). Utilizing an advanced full-tab (tabless) structural design, this cell achieves an ultra-low AC Internal Resistance (≤ 4.0mΩ).
This innovative design significantly minimizes internal heat generation during heavy loads, allowing the cell to support an extraordinary 70A maximum continuous discharge current (with an 80°C temperature cut-off) and a 15A fast charge capability.
With a nominal voltage of 3.6V and a minimum capacity of 4950mAh, the RS50 delivers an unparalleled balance of high energy density, massive power output, and exceptional low-temperature discharge performance down to -40°C. It serves as the ultimate premium power solution for demanding applications such as professional power tools, electric vehicles, and high-capacity portable power stations.
Technical Specifications
| Item |
Specification |
| Model |
INR21700-RS50 |
| Nominal Voltage |
3.6V |
| Standard Capacity |
Min. 4950mAh (0.2C discharge) (Typical ~5000mAh) |
| AC Internal Resistance (ACIR) |
≤ 4.0mΩ (@ 1kHz, Typical ~3.0mΩ) |
| End-of-charge Voltage |
4.2V |
| Discharge Cut-off Voltage |
2.5V |
| Standard Charge Current |
2.5A (0.5C) |
| Standard Discharge Current |
1.0A (0.2C) |
| Rate Charge Current |
8.0A (1.6C) |
| Max. Continuous Charge Current |
15A (3C Fast Charge) |
| Max. Continuous Discharge Current |
70A (With 80°C surface temperature cut-off protection) |
| Cell Dimension |
Max. Diameter: 21.35mm / Max. Height: 70.30mm |
| Cell Weight |
< 67.0g |
| Operating Temperature |
Charge: -20°C ~ 60°C / Discharge: -40°C ~ 80°C |
| Ex-factory Status |
Voltage Range: 3.46V ~ 3.52V (~30% SOC) |
Key Performance & Advantages
- Ultra-Low Internal Resistance: The full-tab construction ensures an ACIR of ≤ 4.0mΩ, dramatically reducing thermal accumulation during extreme high-current discharging.
- Extreme High-Drain Performance: Effortlessly handles continuous 40A discharging while keeping surface temperatures below 70°C. It can even sustain up to a 90A pulse/extreme discharge, delivering roughly 2.2Ah of capacity.
- Exceptional Low-Temperature Resilience:
- At -20°C under a heavy 40A discharge load (100% SOC), the cell maintains an initial voltage above 2.2V within the first 30 seconds.
- At -40°C extreme cold, it reliably supports a 10A discharge current while keeping its initial 30-second voltage above 2.3V.
- Outstanding Cycle Life & Longevity:
- Heavy-Duty Cycle (+8A / -40A): Retains ≥ 80% capacity after 500 cycles (testing shows up to 87.7% retention at 600 cycles).
- Fast Charge/Discharge Cycle (+15A / -30A): Retains ≥ 80% capacity after 500 cycles.
- Deep Cycle (90% DOD, +8A / -10A): Retains ≥ 80% capacity after 1000 cycles.
- Standard Cycle (+2A / -4A): Delivers up to 1500 cycles with ≥ 80% capacity retention.
- Certified Safety Reliability: Fully compliant with strict international safety benchmarks, passing UN38.3 vibration, 1m drop, UL1642 crush (13kN), 2C/6V & 20A/20V overcharge, thermal oven (130°C for 100 min), and multi-resistance short-circuit tests with no fire and no explosion.
Core Applications
- High-Power Electric Tools: Heavy-duty industrial drills, circular saws, lawnmowers, garden machinery, and commercial cleaning equipment.
- Green E-Mobility: High-performance electric motorcycles, premium e-bikes, light electric vehicles (LEVs), and golf carts.
- Portable & Home Energy Storage: High-wattage outdoor power stations, portable solar generators, and emergency home UPS backup systems.
- Specialized Industrial Equipment: Industrial drones, Automated Guided Vehicles (AGVs), and smart warehouse robotics operating in demanding or cold climates.
Critical Safety Instructions & Usage Notice
- Dedicated Charging: Always use a high-quality lithium-ion charger designated for 4.2V cut-off voltages. Never connect the cell directly to a conventional power outlet or attempt reverse charging.
- Voltage Limits: Do not overcharge above 4.2V. In multi-cell assemblies or single applications, never attempt to recharge a cell that has been over-discharged below 1.5V.
- BMS Integration Requirement: The cell must be integrated with a reliable Battery Management System (BMS) or Protection Circuit Module (PCM) providing comprehensive over-charge, over-discharge, over-current, short-circuit, and over-temperature protections.
- Strict Welding Prohibitions: Refer to the official specification diagram for defined prohibited welding areas near the top of the cell. Never apply prolonged heat directly to the cell body with a soldering iron.
- Short Circuit Prevention: Do not store or carry loose cells in pockets or bags alongside metal items like keys, coins, or screws. Terminals should be safely insulated with non-conductive tape during transit and handling.
- Long-Term Storage: For storage exceeding 3 months, remove the cells from the equipment and maintain a State of Charge (SOC) corresponding to a voltage range of 3.45V to 3.95V. Store them in a cool, low-humidity, and temperature-controlled environment.