3.7V Lithium Battery Charger Board | DC-DC Step-Up Boost Module

3.7V Lithium Battery Charger & Boost Module with Type-C USB

Power up your projects with our ultra-compact and high-performance 3.7V Lithium Battery Charger Board! This versatile DC-DC Step-Up Boost Module is perfect for DIY enthusiasts and electronics projects, offering both reliable charging and adjustable voltage output.

Why You Need This Module:

• Compact & Efficient Design: Featuring an ultra-thin, mini design with half-hole screw holes and selected premium materials for durability and performance.
• Versatile Charging: Supports single 3.7V Li-ion batteries (like 18650, polymer), fully charging them to 4.2V.
• Adjustable Output Voltage: Boosts voltage from 4.2V up to 28V, allowing you to power a wide range of devices.
• Smart Charging Protection: Equipped with constant current/constant voltage (CC/CV) charging, over-temperature protection, soft start to limit inrush current, and reverse battery protection.
• Dual Status Indicators: Clear LED indicators (Red CHRG, Blue STDBY) show charging progress, full charge, no battery, and fault status.
• Flexible Input: Choose between a convenient Type-C USB interface or solder joint input on the back. Recommended input voltage is around 5V.
• 0V Activation & Trickle Charge: Safely revive deeply discharged batteries with 0V activation and 2.9V trickle charging.
• High Power Output: Delivers a maximum power of 5W, suitable for various applications.

Key Features & Parameters:

• Operating Temperature: -40°C ~ 80°C
• Input Voltage Range: 4.2V ~ 6.5V
• Output Voltage: 4.2V - 28V (Adjustable)
• Maximum Power: 5W
• Charging Current: Up to 1A programmable linear charge current
• Battery Compatibility: 3.7V Lithium (Li-ion 18650, Polymer, etc.)

Understanding the Charging Indicator Lights:

The module uses two LEDs to indicate its working status:

• Charging: Red light (CHRG) is bright, Blue light (STDBY) is off.
• Fully Charged: Blue light (STDBY) is on, Red light (CHRG) is slightly dim.
• Boost Output Active: Behavior may vary based on output power. Red light might stay on during charging.
• No Connection/No Load: Blue light is on, Red light is slightly dim.

Simple Setup & Battery Connection Guide:

The module supports both Type-C USB and solder joint inputs. Both output ports are identical and wired in parallel.

Connecting Your Battery:

• For Batteries with a Protection Board: Choose a module without built-in discharge protection. After connecting B+ and B-, you must short the 'T' point for proper charging and discharging.
• For Batteries WITHOUT a Protection Board: CRITICAL: Choose a module with discharge protection (if available for this specific product, or ensure your battery has external protection). Connecting the battery to B+ and B- without a protection board requires you NOT to short the 'T' point, as this will disable the discharge protection and can damage your battery.

Adjusting Output Voltage: Once wires are connected, use a small screwdriver to adjust the desired output voltage via the onboard potentiometer.

Important Usage Notes:

• Normal Heating: This product uses linear charging, so some heat generation during operation is normal and safe.
• Parallel Connection Only: Batteries should only be connected in parallel, never in series.
• Optimal Charging Current: The ideal charging current is 0.37C of your battery's capacity (e.g., 400mA for a 1000mAh battery).
• Cable Quality Matters: Ensure charging wires are not too thin or too long to minimize resistance, which can affect battery voltage after charging.
• Good Battery Connection: A solid connection to the battery is crucial to prevent significant voltage drop after charging.
• Heat with High Boost Current: It's normal for the module to generate heat when the boost current is high. Higher power output equals more heat. The chip has built-in overheating protection for safe operation.