HW-357 1S Li-ion Charger with 4.3–27V Step-Up Converter ( Type – C )

From the shop's description

HW-357 Battery Charger and Step-Up Module The HW-357 Battery Charger Step-Up Module combines two functions on one compact board. It charges a single 3.7V lithium battery and boosts its voltage to an adjustable output. The charging section provides linear CC/CV charging up to 4.2V. Meanwhile, the step-up converter can supply an adjustable output from approximately 4.3V to 27V. Key Features Charges one 3.7V Li-ion or LiPo cell Provides an adjustable 4.3V–27V output Supports up to 1A charging current Accepts power through Micro USB Includes separate input solder pads Provides battery and output connection pads Supports output operation during charging Includes charging-status LEDs Offers a compact solution for portable projects Technical Specifications Model: HW-357 / J5019 Battery Configuration: 1S Compatible Battery: 3.7V Li-ion or LiPo Input Voltage: 4.5V–8V DC Recommended Input Voltage: 5V DC Input Connector: Micro USB Battery Charging Voltage: 4.2V ±1% Maximum Charging Current: Up to 1A Charging Method: Linear CC/CV Adjustable Output Range: Approximately 4.3V–27V Maximum Battery-Side Discharge Current: Approximately 2A Quiescent Current: Approximately 0.5mA Operating Temperature: Approximately -20°C to +85°C Dimensions: Approximately 33 × 23 × 5mm Approximate Output Capability The available output current decreases as the selected voltage rises. For example: 5V Output: Up to approximately 1.4A 9V Output: Up to approximately 0.8A 12V Output: Up to approximately 0.6A However, actual performance depends on the battery, input source, cooling, wiring, and converter efficiency. Connection Pads VIN+: Positive charging input VIN-: Negative charging input BAT+: Positive battery terminal BAT-: Negative battery terminal OUT+: Positive adjustable output OUT-: Negative adjustable output How to Use Connect a protected 3.7V lithium cell to BAT+ and BAT-. Check the battery polarity carefully. Supply a stable 5V through Micro USB or VIN. Measure the output with a multimeter. Adjust the potentiometer to the required voltage. Disconnect the load before making large adjustments. Connect the load after confirming the output voltage. Applications Use the HW-357 module for: Portable adjustable power supplies Battery-powered electronics DIY power banks Multimeter modifications Robotics projects Sensor systems Rechargeable test equipment Backup power experiments Embedded electronics Charging and Protection Notes The module can power its output while charging the battery. However, a heavy load may affect charge detection and termination. In addition, the board does not provide reliable low-voltage battery disconnection. Therefore, use one of the following: A protected 18650 battery A separate 1S protection board A suitable 1S BMS An external low-voltage cutoff circuit Package Contents 1 × HW-357 charger and adjustable step-up converter module Important Notes Use this module with one lithium cell only. Do not connect multiple cells in series. The board does not provide complete over-discharge protection. Check the polarity before connecting the battery. Reverse polarity may damage the module. Measure the output voltage before connecting sensitive equipment. Do not exceed the battery’s safe charge or discharge current. Avoid running a heavy load while charging. The module is not a regulated solar charge controller or MPPT controller. Components and LED colors may vary between batches.