Ultra Fire Li-ion Battery Charger- 18650 model
Compact and reliable, the UltraFire DX-2 Charger delivers 4.2V output, dual-channel 300 mA charging, and intelligent polarity detection for safe, fast, and efficient battery charging worldwide (US/UK/EU).
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Reliable Dual-Slot Charger
The UltraFire DX-2 is a versatile two-slot charger built to handle a wide range of lithium batteries, including 18650, 16650, 14500, 16340, and CR123A. With support for global AC input (100–240V, 50–60Hz), it’s ready for use anywhere.
Smart & Safe Charging
Equipped with intelligent charging technology, the DX-2 automatically adjusts to prevent overcharging and protects against reverse polarity. It also supports different output voltages (4.2V, 3.6V, or 3.2V), making it compatible with lithium iron phosphate (LiFePO4) batteries.
Durable & Efficient
Built for reliability, the charger operates smoothly in a wide temperature range and is designed for low-temperature, long-lasting performance, ensuring your batteries get the most out of their lifespan.
Specifications
reviews
🔋 Featured UltraFire Chargers for 18650 Batteries
UltraFire WF‑139 Charger – Compact charger supporting 18650 & other Li-ion sizes; basic safety features and LED status.
UltraFire DX‑4 Battery Charger – A simple multi-slot Li-ion charger from UltraFire family.
💡 Note: UltraFire “chargers for 18650” often include basic safety circuits — but quality may vary. Many users prefer more reliable branded smart chargers.
🧠 Alternative Smart Chargers (Better Performance/Safety)
LiitoKala LII‑M4 4‑Bay Battery Charger – Smart 4-slot charger with automatic current regulation.
XTAR PB2S USB‑C Charger – Popular USB-C smart charger with display + battery health features.
Single 18650 Universal Charger – Ultra-compact option for a single Li-ion cell.
👍 Other Useful Chargers
Eronic 3.7V 18650 Charger – Highly-rated budget charger for 18650/16340/14500 etc.
HZS‑002 Dual 18650 Charger – Simple dual-slot charger.
Hexonix 18650 Charger Module – Module-style charger with LED.
📊 18650 Charger Overview (Visual-Ready Info)
Here’s a quick infographic-style summary you can use in presentations or reference sheets:
| Feature | Typical 18650 Charger (UltraFire & Similar) |
|---|---|
| 🔌 Input Voltage | ~100-240 VAC (some USB input) |
| 🔋 Supported Cell Types | 18650 Li-ion + smaller sizes (14500, 16340 etc) |
| 📊 Charging Voltage | ~4.2 V (standard for Li-ion) |
| ⚡ Typical Charge Current | ~450-550 mA per slot |
| 🛡️ Safety Protections | Over-charge, short-circuit, LED indicators |
| 🧠 Smart Features | LCD/LED status, auto stop on full charge (on smart models) |
| 📦 Compatibility | 18650, 14500, 16340, 17500, 17670, CR123A (varies by model) |
🧠 How It Works (Simple Explanation)
Insert the 18650 cell(s): Align + and − correctly.
Power On: Charger draws AC mains or USB-C power.
Charging Cycle: Most use Constant-Current / Constant-Voltage (CC/CV) method:
Starts at steady current → then reduces current at ~4.2 V to avoid overcharge.
Auto Stop / Indicator: LEDs or LCD show charge progress and stop when full.
⚠️ Safety & Practical Tips
✅ Only use Li-ion-specific chargers — do not use chargers for NiMH or lead-acid.
✅ Check the charger stops at ~4.2 V; overcharging can be dangerous.
✅ Avoid low-quality/unbranded chargers that don’t shut off at full voltage.
✅ 18650 cells should be stored ~50% charged for longer life.
⚠️ Always charge in a fire-safe area and don’t leave unattended.
📌 Quick Terms
18650 – Standard rechargeable Li-ion cell size (18 mm × 65 mm).
CC/CV Charging – Safe lithium charging method used by smart chargers.
Protection Circuit – Prevents overcharge/short-circuit.