FNIRSI FNB48S – Compact USB Digital Tester for Fast Charging, Voltage, Current & Protocol Detection with OLED Display

The FNIRSI FNB48S is a compact, intelligent, and professional-grade USB digital tester engineered to deliver real-time diagnostics and complete visibility into your USB power systems. Whether you're a technician, electronics enthusiast, engineer, or an everyday user seeking deeper control over charging performance, the FNB48S is your all-in-one solution to analyze, verify, and optimize USB power delivery like a pro.

Ultimate USB Charging Transparency in Your Hands

Say goodbye to blind charging! With the FNB48S, you can detect charging protocols, monitor live voltage and current, track energy usage, and test charger/cable quality — all in a sleek device that fits in your pocket.

Equipped with a bright OLED display, it presents critical power metrics instantly and clearly, while supporting advanced fast-charging standards including QC, PD, SCP, AFC, and FCP.

Key Features & Functions:

Fast Charge Protocol Detection

• Detects and displays popular fast-charging protocols:

  • PD 2.0 / 3.0

  • Qualcomm QC2.0 / QC3.0

  • Huawei SCP / FCP

  • Samsung AFC, VOOC, and others

• Perfect for identifying fake or limited-capability chargers

Accurate Voltage & Current Monitoring

• Voltage range: 4.5V – 30V

• Current range: 0A – 5.1A

• Power range: 0 – 150W

• Real-time display of Voltage (V), Current (A), Power (W), Capacity (mAh), Energy (Wh), Load Resistance (Ω), and Charging Time

OLED Display with Intuitive Interface

• High-resolution OLED ensures clear visibility even in low light

• Simple toggle buttons to switch between display modes

• Smart layout for quick information scanning

Data Logging & Power Statistics

• Automatically records cumulative power usage

• Monitors total energy transferred during charging sessions

• Ideal for evaluating power banks, battery packs, or long-term charger performance

Dual-Port Compatibility (USB-A & Type-C)

• Supports both standard USB-A and modern USB Type-C ports

• Bi-directional connection enables testing of both input and output power paths

• Compatible with USB-C to USB-A adapters for flexible use

Protection & Reliability

• Built-in safety features:

  • Overvoltage protection

  • Overcurrent detection

  • Short-circuit prevention

• Durable PCB design with long operational lifespan

Perfect For:

• ? Testing power banks for real capacity

• ? Verifying fast charger compatibility and performance

• ? Diagnosing USB charging issues or failures

• ? Analyzing real-time energy usage in embedded systems

• ? Repair labs, R&D testing, and tech support workflows

• ? Enthusiasts comparing charging cables, chargers, and devices

Technical Specifications: