Samsung INR21700-50E 5000mAh 3.7V 21700 Battery – 10A Continuous for Flashlights, Power Banks, Fans & Toys (Flat Top, Button Top, Nickel Tab)

The Industry Gold Standard for High‑Capacity 21700 Cells

The Samsung INR21700-50E is widely regarded as the benchmark in the 21700 category. With a genuine 5000mAh capacity and a verified 10A continuous discharge, this cell delivers the endurance that flashlights, power banks, fans, and motorized toys demand — without the voltage sag that plagues lesser cells. It stores approximately 18.5 watt‑hours of energy, nearly 2.5 times what a standard 2000mAh 18650 can hold, making it the go‑to choice for builders and enthusiasts who refuse to compromise on runtime. Whether you are assembling a high‑capacity USB‑C power bank, feeding a turbo flashlight, or powering a portable fan through a long work shift, the 50E provides the stable, long‑lasting energy you need.

Unprotected, Uncompromised Performance

Like all Samsung cylindrical cells intended for pack building and enthusiast use, the 50E is supplied as an unprotected bare cell. This keeps the overall length at the standard 70mm (flat top) and ensures the lowest possible internal resistance. The absence of a protection PCB means the cell fits effortlessly into any 21700‑compatible device — from tightly machined flashlight tubes to compact power bank enclosures and fan battery bays. It also means you must pair the cell with a quality charger that stops at exactly 4.2V and only install it in devices that have their own low‑voltage cutoff. Virtually every modern LED flashlight, USB‑rechargeable fan, DIY power bank board, and electronic toy already includes this protection, making the 50E a safe, drop‑in upgrade.

Three Terminal Options for Total Flexibility

Every device is different, so we provide three distinct positive‑terminal configurations:

• Flat Top: The completely flush positive terminal. Required for ultra‑tight battery tubes, devices with pogo‑pin contacts, and custom spot‑welded battery packs. Most high‑end flashlights (ZebraLight, Noctigon, Emisar) and power bank kits specifically require flat‑top cells.

• Button Top: A raised positive nipple (~1.5mm) that locks securely into spring‑loaded compartments and easily passes mechanical reverse‑polarity guards. Ideal for many consumer flashlights, some fan holders, and toy battery trays.

• Nickel Tab: Both positive and negative terminals come pre‑welded with pure nickel strips, ready for soldering or additional spot welding. This is the turn‑key solution for building DIY power banks, 2S/3S packs for toys, or replacing cells in custom electronics.

Where 5000mAh and 10A Shine

The 50E's 5000mAh capacity provides remarkable runtime across a broad range of devices. In a single‑LED flashlight on a 300‑lumen medium mode, expect over 5 hours of continuous light; on a low 50‑lumen setting, the cell illuminates an entire night — 12 hours or more. A USB desk fan on low speed spins for 10–12 hours, keeping you comfortable through a full shift. In a DIY power bank configured as a 1S or 2S pack, a single 50E can charge a smartphone 1.5 to 2 times, and a multi‑cell bank can keep tablets and cameras running for days. Motorized toys and ride‑on vehicles also see dramatic runtime improvements when powered by 50E packs. The 10A continuous discharge ensures that even when your device demands higher current — such as a flashlight on turbo or a fan on high — the cell delivers steady voltage without premature step‑down or power loss.

Samsung Reliability and Advanced INR Chemistry

Under the nickel‑plated steel shell, Samsung's proven INR (Nickel‑Manganese‑Cobalt) chemistry provides a stable 3.7V nominal voltage and an exceptionally flat discharge curve. With an internal resistance of ≤30mΩ, voltage sag at 10A is only about 0.3V — your devices stay in regulation longer, and your beams stay brighter. The 50E is rated for over 500 full charge/discharge cycles with at least 70% capacity retention. Its low self‑discharge rate means you can store spare cells at 3.6–3.7V for months, and they will still wake up ready for your next project or power outage. Built‑in safety features — a PTC thermistor, resealable safety vent, and CID (Current Interrupt Device) — provide multiple layers of passive protection against over‑current, over‑pressure, and short circuits, giving you confidence in every charge cycle.

Key Features

• Genuine Samsung INR21700-50E Cell
  Industry‑leading 5000mAh capacity with 10A continuous discharge. Trusted by flashlight enthusiasts, power bank builders, and device manufacturers worldwide.

• 5000mAh High Capacity (18.5Wh)
  Up to 2.5× the energy of a 2000mAh 18650. Delivers 5+ hours of 300‑lumen flashlight light, 10–12 hours of fan cooling, or 1.5–2 smartphone charges per cell.

• 10A Continuous / 15A Pulse Discharge
  Verified 10A continuous output handles medium‑drain loads with ease. Can pulse up to 15A for short bursts, providing extra headroom when devices demand a momentary surge.

• Unprotected Bare Cell — Standard 70mm Length
  Fits all 21700‑compatible devices. Lower internal resistance ensures cooler operation and efficient power delivery. Requires a 4.2V Li‑ion charger and device with low‑voltage cutoff.

• 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 DIY packs. Full compatibility across the 21700 ecosystem.

• Stable INR (NMC) Chemistry
  Samsung's proven Nickel‑Manganese‑Cobalt formulation provides excellent thermal stability, high energy density, and long cycle life.

• Low Internal Resistance (≤30mΩ)
  Voltage drop at 10A is only ~0.3V. Your devices stay regulated longer, and your beams stay brighter throughout the entire discharge.

• 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 adventure or project.

• Multi‑Layered Passive Safety
  Built‑in PTC thermistor, resealable safety vent, and CID protect against over‑temperature, over‑pressure, and internal short circuits.

• Nickel‑Plated Steel Can
  Corrosion‑resistant and drop‑resistant. Engineered to withstand the rigors of portable electronics, power tools, and outdoor environments.

Technical Parameters

Applications

1. High‑Performance LED Flashlights
   Drop a 50E into any 21700‑compatible flashlight and enjoy runtime that lasts from dusk to dawn. On medium mode, it delivers 5+ hours of steady light; on low, it runs all night. The 10A output easily handles turbo modes without premature step‑down. Flat top fits ultra‑tight enthusiast tubes; button top locks securely in spring‑loaded hosts.

2. DIY Power Banks & USB‑C Chargers
   The 50E is the preferred cell for building high‑capacity power banks. A single cell provides enough energy to charge a smartphone 1.5–2 times. Use multiple cells in parallel for tablets, cameras, or multi‑day camping trips. The nickel tab variant makes spot welding fast and reliable.

3. Portable Fans for All‑Day Cooling
   USB desk fans, camping fans, and job‑site fans run 10–12 hours on low speed with a 50E. The stable 10A output keeps airflow strong even on high settings. Flat top is often required for recessed fan battery bays.

4. Motorized Toys & Ride‑On Vehicles
   Upgrade your child's RC car, robot, or ride‑on toy with a 2S or 3S pack of 50E cells. The 5000mAh capacity dramatically extends playtime, and the 10A discharge provides the current needed for startup surges and sustained driving.

5. Camera Monitors, Video Lights & Accessories
   External field monitors, LED panels, and camera battery adapters that accept 21700 cells benefit from the massive capacity and stable voltage. Fewer battery swaps mean uninterrupted shooting. Many camera adapters require flat‑top cells.

6. Portable Medical & Industrial Devices
   Handheld scanners, portable nebulizers, and thermal printers that rely on 21700 power appreciate the combination of long runtime and reliable 10A output, ensuring consistent operation through extended shifts.

7. Emergency Backup & Off‑Grid Power
   Store a few charged 50E cells in a waterproof case with a USB charger board. When the grid fails or you're off‑grid, you have a reliable source of power for lights, phones, and radios.

FAQ

Q1: Is this a genuine Samsung 50E cell?
A: Yes. We source directly from authorized distributors. Each cell is a genuine Samsung INR21700-50E, manufactured in Korea. You can verify the capacity and performance with any professional battery analyzer.

Q2: Can the 50E really deliver 15A? I see "3C" on some listings.
A: The Samsung 50E is rated for 10A continuous discharge. The "3C" (15A) figure refers to the maximum pulse discharge for very short bursts (a few seconds). We state the honest continuous rating. For applications that require 15A+ continuously, we recommend high‑drain cells like the Samsung 40T or Molicel P42A.

Q3: Why is this battery unprotected? Is it safe?
A: Samsung 50E cells are designed as bare cells for pack building and enthusiast use. Removing the external protection PCB keeps the cell at the standard 70mm length and minimizes internal resistance. It is completely safe when used correctly: charge only with a quality 4.2V Li‑ion charger, and use only in devices that have built‑in low‑voltage cutoff — a standard feature in modern flashlights, power bank boards, USB fans, and toys. The cell itself includes a PTC thermistor, safety vent, and CID for passive protection.

Q4: Which terminal option should I choose — Flat Top, Button Top, or Nickel Tab?
A: Flat Top for devices with tight battery tubes, pogo‑pin contacts, and power bank kits. Button Top for spring‑loaded compartments and devices with reverse‑polarity rings. Nickel Tab if you are soldering or spot‑welding the cell into a custom pack. When in doubt, consult your device manual or measure the battery compartment.

Q5: Can I use this battery in an 18650 device?
A: No. A 21700 cell (21mm × 70mm) is physically larger than an 18650 (18mm × 65mm). Your device must explicitly support 21700 batteries. Never force a 21700 into an 18650 tube, as this can damage both the cell and the device.

Q6: How many times can I recharge a 50E?
A: The cell is rated for over 500 full charge/discharge cycles while retaining at least 70% of its original capacity. In practical terms, with typical partial charging, this translates to years of regular use.

Q7: Can I use the 50E in an e‑bike or electric scooter?
A: The 50E is an energy‑dense cell rated for 10A continuous. It can be used in low‑power e‑bikes or scooters when configured in a large parallel pack (e.g., 4P or 5P). For high‑power e‑bikes that draw 15A+ per cell, we recommend high‑drain cells such as the Samsung 40T, 30T, or Molicel P42A.

Q8: How should I store spare cells?
A: Store them in a plastic battery case or silicone sleeve, away from metal objects and moisture. For storage longer than one month, bring the voltage to about 3.6–3.7V (roughly 50% charge). Check every 3 months and recharge if the voltage drops below 3.0V. Never store a fully depleted cell.

Q9: Can I bring this battery on an airplane?
A: Yes. At 18.5Wh, it is well under the 100Wh IATA limit for carry‑on luggage. Insulate the terminals with tape or a plastic case and carry the cells in your hand luggage.