XTAR VC8 8-Slot Smart Charger & 8x Samsung 20S Flat Top 18650 Battery Kit (30A High Drain)

Why This Bundle

The Samsung 20S is one of the hardest-hitting 18650 cells available — built for devices that demand serious continuous current. A set this size deserves a charger that can handle every cell at once while keeping tabs on their health. This bundle pairs 8 genuine Samsung 20S Flat Top batteries with the XTAR VC8, an 8-bay Type-C charger with real capacity testing, internal resistance detection, and independent monitoring for every slot — ready to use straight out of the box.

This listing is for Flat Top. Looking for Button Top? Click here to buy:  Samsung INR18650-20S Button Top + XTAR VC8 Bundle.

Samsung INR18650-20S (Flat Top) Specifications

Note: This is an extremely high-drain 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 VC8

• Type-C input with QC3.0 support: up to 3A on a single bay when battery resistance is low enough
• 5 adjustable current levels: 3A×1 / 2A×2 / 1A×4 / 0.5A×8 / 0.25A×8 — manually selectable to match your charging needs
• 8 independent charging slots: each bay monitored and controlled separately
• Real Capacity Test (Grading Mode): on CH1–CH4, the VC8 tests true capacity through a charge–discharge–charge cycle at a stable 300mA discharge current, revealing whether a battery's stated capacity is accurate
• Storage Mode: charges or discharges batteries to their rated storage voltage to maximize battery lifespan
• Smart Battery Type Detection: automatically identifies the battery and selects the optimal charging strategy
• VA LCD Display: real-time voltage, current, mode, battery type, internal resistance, and charged capacity for every slot
• Multiple Safety Protections: over-current, overcharge, over-voltage, and short-circuit protection; automatically stops after full charge; reverse-connection and over-discharge activation for protected cells
• Built from fire-retardant PC/ABS material, with a built-in "Three-Stage Lithium Battery Charging System" (Patent No. 201720828840.6)

XTAR VC8 – Supported Battery Types & Voltage

Compatible with 3.6V/3.7V Li-ion/IMR/INR/ICR batteries, including the Samsung 20S (18650) in this bundle:

10440, 14500, 14650, 16340, 17500, 17670, 18350, 18490, 18500, 18650, 18700, 20700, 21700, 22650, 25500, 26650

Also compatible with 1.2V Ni-MH/Ni-Cd batteries: AAAA, AAA, AA, A, SC, C

End-of-charge voltage: 4.20±0.05V (Li-ion) / 1.45±0.1V (NiMH) · End-of-charge current: <120mA

Compatibility Notes

The VC8's slider-style contacts accommodate battery lengths from 32mm to 76mm, fitting Flat Top batteries securely without any adapter. Samsung 20S Flat Top cells measure about 65.0mm, well within the VC8's compatible range. All 8 cells in this bundle can be charged simultaneously across the charger's 8 independent bays.

What's Included

• Samsung INR18650-20S Flat Top Battery × 8
• XTAR VC8 Charger × 1
• USB-A to USB-C Charging 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 VC8
• The Samsung 20S is an extreme high-drain cell intended strictly for compatible, purpose-built devices designed for 30A continuous discharge — do not use in unauthorized or modified equipment
• Flat Top batteries are commonly used in devices with spring or flat-contact battery holders (e.g., battery packs and power tools) — check your device's terminal requirements before use

FAQ

Q: Can the XTAR VC8 charge Samsung 20S Flat Top batteries safely? A: Yes. The VC8 automatically detects Li-ion/IMR chemistry and applies the correct charging voltage (4.2V) and current for 20S cells, with independent monitoring on each of its 8 slots.

Q: Can I charge all 8 batteries at the same time? A: Yes. The VC8 has 8 independent slots. At the default automatic setting, all 8 can charge simultaneously at up to 0.5A per slot; manually selecting a higher current level will use fewer slots at once (e.g., 3A on 1 slot, 2A on 2 slots, or 1A on 4 slots).

Q: What's the difference between Flat Top and Button Top batteries? A: The only difference is the shape of the positive terminal — Flat Top is level for full-surface contact, while Button Top has a raised nub. Capacity, voltage, and discharge rate are identical.

Q: Will Flat Top batteries sit properly in the VC8 charger slots? A: Yes. The VC8's slider-style contacts are designed to accommodate both Flat Top and Button Top cells without any adapter or modification.

Q: How do I test if a 20S battery has lost capacity? A: Use the VC8's Grading Mode on CH1–CH4. It runs a charge–discharge–charge cycle to measure true capacity, so you can identify batteries that no longer meet their rated mAh.

Q: Is 30A continuous discharge safe for everyday devices? A: No — the Samsung 20S is one of the highest-drain 18650 cells available and is intended strictly for devices specifically engineered for extreme continuous discharge, such as certain power tools, high-output flashlights, and professional battery pack assemblies. Always confirm your device's current requirements before use.

Q: Does the VC8 require a special power adapter for fast charging? A: For the fastest speeds (2A/3A settings), a QC3.0-compatible USB-C adapter is required. Without QC3.0, charging current will be limited.

Q: What's in the box? A: 8 Samsung INR18650-20S Flat Top batteries, 1 XTAR VC8 charger, a USB-A to USB-C charging cable, and a user manual.