Product Description
The Ultimate Fusion of Capacity and Current
The Samsung INR21700-50S shatters the old rules of lithium‑ion cell design. Until now, choosing a 21700 battery meant sacrificing either capacity or current: you could have a 5000mAh cell that topped out at 10A, or a high‑drain cell that gave you 35A but only 4000mAh. The 50S delivers both. With a genuine 5000mAh capacity and a verified 25A continuous discharge, it provides the massive energy reserve of an ultra‑high‑capacity cell with the current capability of a serious high‑drain performer. This makes it the ideal single‑cell solution for devices that refuse to compromise: turbo flashlights that demand both lumens and runtime, portable fans that run for shifts, cordless power tools that need startup punch, and drones that require sustained power without voltage sag.
25A That Backs Up the 5000mAh
The 25A continuous rating isn't just a number — it's the current that keeps your devices in regulation. With an internal resistance of ≤20mΩ, the 50S experiences minimal voltage drop even under heavy loads. At 25A, the voltage sags by only 0.5V, meaning your turbo flashlight won't step down prematurely, your drill won't stall when driving a long screw, and your drone's motors will keep spinning at full RPM through an entire battery pack. The cell can pulse significantly higher for instantaneous surges, making it more than capable of handling the startup spikes of power tools and the full‑throttle punch‑outs of FPV quads. Samsung's advanced INR chemistry also ensures that heat generation remains manageable, even during sustained high‑current use.
Unprotected, Enthusiast‑Grade Design
The 50S is supplied as an unprotected bare cell, exactly as Samsung intends for pack builders and advanced users. Omitting the external protection PCB keeps the cell's length at the standard 70.0mm (flat top) or 71.0mm (button top) and eliminates the added resistance and potential current‑limiting trip points that can plague protected cells during high‑drain applications. This design requires responsible handling: always use a quality charger that terminates at exactly 4.2V, and only install the cell in devices that have built‑in low‑voltage cutoff — a feature already present in virtually all modern LED flashlights, USB‑rechargeable fans, brushless power tools, and drone electronics. The cell itself incorporates a PTC thermistor, resealable safety vent, and CID for multi‑layered passive protection.
Three Terminal Options, One Perfect Fit
To guarantee compatibility with any device, we provide three distinct positive‑terminal configurations:
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Flat Top: The positive terminal sits completely flush with the cell body. Required for ultra‑tight flashlight tubes, devices with pogo‑pin contacts, and custom spot‑welded battery packs. Many enthusiast flashlights (ZebraLight, Noctigon, Emisar, etc.) and drone battery builds specifically demand flat‑top cells.
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Button Top: A raised positive nipple (~1.5mm) locks securely into spring‑loaded battery compartments and easily passes mechanical reverse‑polarity guards. Perfect for consumer flashlights, fan battery holders, and some tool adapters.
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Nickel Tab: Both terminals come pre‑welded with pure nickel strips, ready for soldering or additional spot welding. This turn‑key option is ideal for building high‑current packs for cordless tools, drones, or custom power banks.
Where the 50S Transforms Your Experience
With 5000mAh (18.5Wh) on tap, a single 50S cell can power a 300‑lumen flashlight for over 5 hours, a portable fan on low speed for 10–12 hours, or a cordless drill through dozens of screws on a single charge. In a drone or high‑power RC model, the 50S provides the sustained current necessary for aggressive flight maneuvers while delivering flight times that rival dedicated energy cells. For DIY builders, the nickel tab variant simplifies pack assembly, and the cell's consistent 5000mAh capacity makes cell matching straightforward. The 50S is also an excellent candidate for high‑power power banks, portable inverters, and medical devices that require both peak current and long runtime.
Long‑Term Reliability from Samsung INR Chemistry
Under the nickel‑plated steel shell, Samsung's proven INR (Nickel‑Manganese‑Cobalt) formulation provides a stable 3.7V nominal voltage and an exceptionally flat discharge curve. The cell is rated for over 500 full charge/discharge cycles with ≥70% capacity retention. Low self‑discharge means you can store spare cells at 3.6–3.7V for months without significant power loss. Built‑in safety features — including a PTC thermistor, resealable safety vent, and CID (Current Interrupt Device) — provide multiple layers of passive protection, giving you confidence in every charge cycle.
Key Features
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5000mAh + 25A: No More Compromises
Industry‑first combination of ultra‑high capacity and serious high‑drain performance. Genuine 5000mAh delivers 5+ hours of flashlight runtime or 10–12 hours of fan cooling, while 25A continuous discharge feeds power‑hungry tools and drones without sag.
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25A Continuous / 35A Pulse Discharge
Verified 25A continuous output with the ability to pulse up to 35A for short bursts. Handles the startup spikes of cordless drills and the full‑throttle surges of racing drones.
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Unprotected Bare Cell — Standard 70mm Length
Fits all 21700‑compatible devices. Lower internal resistance ensures cooler operation and efficient power delivery. Requires a quality 4.2V Li‑ion charger and device with low‑voltage cutoff.
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Three Terminal Options: Flat Top, Button Top & Nickel Tab
Flat Top for tight tubes and pogo‑pin contacts. Button Top for spring‑loaded compartments. Nickel Tab for ready‑to‑weld custom battery packs. Complete versatility across all 21700 applications.
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Advanced Samsung INR (NMC) Chemistry
Provides stable 3.7V nominal voltage, flat discharge curve, and excellent thermal stability — trusted in professional tools, drones, and electric vehicles.
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Low Internal Resistance (≤20mΩ)
Voltage drop at 25A is only ~0.5V, keeping your devices in regulation and your performance at its peak throughout the discharge cycle.
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500+ Cycle Life & Low Self‑Discharge
Recharge over 500 times with minimal capacity fade. Holds charge for months when stored at 3.6–3.7V — always ready for your next project or power outage.
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Multi‑Layered Passive Safety
Built‑in PTC thermistor, resealable safety vent, and CID protect against over‑current, over‑pressure, and internal short circuits.
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Rugged Nickel‑Plated Steel Can
Corrosion‑resistant and impact‑resistant. Designed to withstand the vibrations, drops, and temperature swings of power tools, drones, and outdoor environments.
Technical Parameters
Applications
1. High‑Performance Flashlights
For turbo flashlights that demand maximum lumens without sacrificing runtime. The 50S feeds FET‑driven and multi‑emitter lights with 25A of current while the 5000mAh capacity keeps the beam shining for hours. Flat top fits ultra‑tight enthusiast tubes; button top locks into spring‑loaded hosts.
2. Portable Fans for All‑Day Cooling
USB desk fans, camping fans, and job‑site fans benefit from the 50S's massive capacity and stable voltage. Low speed delivers 10–12 hours of breeze; high speed stays strong without sag. Flat top is often required for recessed fan battery bays.
3. Cordless Power Tools
Replace worn cells in drills, impact drivers, and small saws with 50S cells. The 25A continuous discharge handles the startup spikes and sustained loads of professional tools, while the 5000mAh capacity provides meaningful runtime. Nickel tabs are perfect for spot‑welding into 5S1P or 5S2P packs.
4. Racing Drones & FPV Quadcopters
The 50S offers a unique balance for drone pilots: high capacity for longer flight times and high current for aggressive throttle response. Build 4S or 6S packs for freestyle, racing, or long‑range quads.
5. High‑Power Power Banks & DIY Projects
Build a multi‑cell power bank that can fast‑charge laptops and tablets while holding enough energy for multiple smartphone charges. The nickel tab variant simplifies pack assembly, and the 5000mAh per cell reduces the total number of cells needed.
6. RC Models & Motorized Toys
RC cars, trucks, boats, and robots benefit from the 50S's ability to deliver both sustained current for speed and long runtime for extended play sessions.
7. Portable Medical & Industrial Equipment
Devices that require both peak current for motors/actuators and long runtime — such as portable ventilators, infusion pumps, and barcode scanners — are well‑served by the 50S.
FAQ
Q1: Is the Samsung 50S really 25A continuous? How does it compare to the 50E or 40T?
A: Yes, Samsung rates the 50S at 25A continuous. It sits between the 50E (5000mAh, 10A) and the 40T (4000mAh, 35A). The 50S gives you the full 5000mAh of the 50E with 2.5 times the current, or 25% more capacity than the 40T with a still‑very‑high 25A drain. It's the perfect choice when you refuse to compromise on either runtime or power.
Q2: Why is this cell unprotected? Is it safe?
A: The 50S is designed as a bare cell for pack building and enthusiast devices. Omitting the protection PCB keeps the cell short, reduces internal resistance, and prevents unwanted current limiting. It's safe when used with a quality 4.2V charger and in devices that have built‑in low‑voltage cutoff — which includes virtually all modern flashlights, fans, power tools, and drones. The cell's PTC, vent, and CID provide passive protection.
Q3: Which terminal option do I need — Flat Top, Button Top, or Nickel Tab?
A: Flat Top for tight tubes and pogo‑pin contacts, and for spot‑welded packs. Button Top for spring‑loaded compartments with reverse‑polarity rings. Nickel Tab if you're soldering or spot‑welding the cell into a custom pack. Check your device manual if unsure.
Q4: Can I use the 50S in a device designed for 18650?
A: No. A 21700 cell (21mm × 70mm) is larger than an 18650 (18mm × 65mm). The device must explicitly support 21700s. Never force a 21700 into an 18650 tube.
Q5: How many cycles can I get from a 50S?
A: Samsung rates the cell for ≥500 full charge/discharge cycles with ≥70% capacity retention. In real‑world partial‑charging use, you'll likely see many more cycles over years of service.
Q6: Can I charge the 50S at 5A?
A: Yes, the maximum charge current is 5A (1C). For best longevity, however, we recommend the standard 2.5A (0.5C) charge. Faster charging generates more heat and may slightly reduce long‑term capacity.
Q7: How should I store spare cells?
A: In a plastic case or silicone sleeve, away from metal and moisture. For storage over 1 month, bring the voltage to ~3.6–3.7V (about 50% charge). Check every 3 months and recharge if below 3.0V. Never store fully depleted.
Q8: Can I take this battery on a plane?
A: Yes, 18.5Wh is well under the 100Wh IATA limit. Carry in hand luggage with terminals insulated.
