Why This Bundle
The Samsung 50S steps up from the 50E with the same 5000mAh capacity but a significantly higher discharge ceiling — 20A continuous without a temperature cutoff, or up to 35A with an 80°C thermal cutoff — making it a stronger choice for e-bikes, power tools, and drones that need both energy and real current delivery. This bundle pairs 2 genuine Samsung INR21700-50S batteries with the XTAR MC2 — a compact, USB-C powered dual-slot charger that intelligently adjusts charging current and includes 0V activation for over-discharged cells. Everything you need to charge and maintain your cells, ready out of the box.
Samsung INR21700-50S Specifications
| Item |
Spec |
| Model |
Samsung INR21700-50S (Flat Top) |
| Nominal Capacity |
5000mAh |
| Minimum Capacity |
4900mAh |
| Nominal Voltage |
3.6V |
| Max Continuous Discharge |
20A (no temp cutoff) / 35A (80°C temp cutoff) |
| Standard Charge Current |
2.5A |
| Rapid Charge Current |
6A |
| Charge Cutoff Voltage |
4.20V |
| Discharge Cutoff Voltage |
2.5V |
| Chemistry |
Li-ion, high-capacity/high-discharge |
| Cell Size |
21700 (approx. Φ21.25mm × 70.6mm, max weight 72g) |
| Terminal Type |
Flat Top only |
| Protection Circuit |
None (unprotected cell) |
| Typical Use |
EVs, e-bikes, drones, power tools, e-mobility, and other high-capacity high-drain battery pack builds |
Note: Samsung's own product positioning lists the 50S for EV, e-bike, drone, power tool, and e-mobility applications, and explicitly states it is not intended for e-cigarettes, flashlights, RC cars, or electric skateboards.
This is an unprotected cell — avoid mixing with batteries of a different brand, model, or charge state, and inspect the wrap for damage before every use to prevent short circuits.
The Charger: XTAR MC2
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USB-C input: DC 5V/1A, works with USB wall adapters, power banks, laptops, and car chargers
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Dual independent charging slots: charge two batteries simultaneously with individual monitoring
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Intelligent current adjustment: automatically sets charging current to 0.5A×2 (with a 5V/1A source) or 0.25A×2 (with a lower-power source)
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0V Activation: helps recover batteries that have over-discharged
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Multiple safety protections: reverse-polarity protection, short-circuit protection, temperature monitoring
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Compatible with protected 20700/21700 cells (current USB-C generation)
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Ultra-compact & lightweight: just 24g, 92mm × 40mm × 32mm
XTAR MC2 – Supported Battery Types & Voltage
Compatible with 3.6V/3.7V Li-ion batteries, including the Samsung 50S (21700) in this bundle, across a length range of approximately 31mm to 71.4mm — covering everything from 10440 up through 21700 and 26650 cells.
End-of-charge voltage: 4.20±0.05V · End-of-charge current: ≤120mA
Compatibility Notes
The MC2's charging slots accommodate battery lengths up to roughly 71.4mm, which comfortably fits the 50S's 70.6mm length, including its Flat Top terminal.
Important: The 50S supports a standard charge current of 2.5A (up to 6A on rapid charge), but the MC2 charges at a maximum of 0.5A per slot. Charging a 5000mAh cell at 0.5A will take considerably longer than on a high-current charger — expect several hours per full charge. The MC2 is best suited here as a portable, gentle-charging backup rather than your primary fast charger for these cells.
What's Included
- Samsung INR21700-50S Battery × 2
- XTAR MC2 Charger × 1
- USB Cable × 1
- User Manual × 1
Safety Tips
- Store batteries in a proper case, keeping them away from loose metal objects to prevent short circuits
- Never disassemble, puncture, burn, or submerge the batteries
- Charge only with a genuine, compatible charger such as the XTAR MC2
- The 50S is an unprotected cell intended for compatible, purpose-built devices such as EVs, e-bikes, drones, and power tools — it is not intended for e-cigarettes, flashlights, RC cars, or electric skateboards
- Never discharge below 2.5V or charge above 4.2V
FAQ
Q: Can the XTAR MC2 charge Samsung 50S batteries safely? A: Yes, the MC2 correctly detects and charges 3.6V/3.7V Li-ion cells including 21700s like the 50S, with proper 4.2V cutoff voltage. Just be aware the charging current is much lower than the 50S's rated charge current, so a full charge will take longer than it would on a high-current charger.
Q: Is the Samsung 50S suitable for flashlights? A: No. Samsung's own product positioning explicitly states this cell is not intended for flashlights, RC cars, or electric skateboards. It's built for EVs, e-bikes, drones, power tools, and e-mobility applications.
Q: How does the 50S compare to the 50E? A: Both share the same 5000mAh capacity, but the 50S has a meaningfully higher discharge ceiling — 20A continuous (35A with thermal cutoff) versus the 50E's 9.8A — making the 50S the better pick for applications that need more current alongside the capacity.
Q: Will a 21700 battery actually fit in the MC2? A: Yes. The MC2's slots accommodate batteries up to roughly 71.4mm in length, which covers the 50S's 70.6mm length comfortably.
Q: How long will it take to fully charge a 50S on the MC2? A: Since the MC2 charges at up to 0.5A per slot and the 50S has a 5000mAh capacity, expect a full charge to take considerably longer than the 50S's rated charge current would suggest — likely several hours. This charger is better suited as a portable or backup option for these cells rather than a primary fast charger.
Q: Can I charge both batteries at the same time? A: Yes. The MC2 has 2 independent slots and can charge both simultaneously, automatically adjusting current based on your power source.
Q: What's in the box? A: 2 Samsung INR21700-50S batteries, 1 XTAR MC2 charger, a USB cable, and a user manual.
