BQ25185 USB / DC / Solar Li-ion Battery Charger with 3.3V Buck Converter Board

Short Description

The BQ25185 charger board is a compact power management solution designed for single-cell lithium-ion or lithium-polymer batteries. It supports charging from USB Type-C, DC input, or solar panels and includes an onboard 3.3V buck converter, allowing projects to run directly from the battery without requiring a separate regulator board.

Key Features

• Single-cell Li-ion / LiPo battery charger

• Supports USB, DC, and solar charging inputs

• Integrated power-path management

• Onboard 3.3V buck converter

• Adjustable charge current

• Regulated load outputs

• Status indication LEDs

Technical Specifications

Charging and Power

• Charger IC: BQ25185

• Buck Converter IC: TPS62569

• Battery Type: Single-cell Li-ion / LiPo

• Recommended Battery Capacity: 500mAh or higher

• USB Input: USB Type-C, 5V up to 1A

• DC / Solar Input Voltage: 5V to 18V

• Default Charge Current: 1A

• Optional Charge Current: 500mA (via jumper)

Outputs

• Load Output Voltage:

  • 3.0V to 4.5V (power-path output, up to 1A)

• Regulated Output Voltage:

  • 3.3V (buck converter, up to 1A)

Indicators and Control

• Charging Status LED: Orange

• Fault Indicator LED: Red

• 3.3V Output Indicator LED: Green

• Enable Pad: Controls 3.3V buck converter

Connectors and Interfaces

• Battery Connector: JST PH 2-pin

• USB Connector: USB Type-C

• Load Output: Terminal blocks

• DC / Solar Input: Edge pads

Applications / Use Cases

• Battery-powered IoT devices

• Portable embedded systems

• Solar-powered sensor nodes

• Wearable electronics

• 3.3V microcontroller projects

• Remote data loggers

How to Use

• Connect a single-cell Li-ion or LiPo battery to the JST PH connector

• Power the board using USB Type-C, DC input, or a compatible solar panel

• Use the terminal block outputs to power your circuit

• Optionally adjust the charge current by modifying the onboard jumper

Package Includes

• 1 x BQ25185 USB / DC / Solar charger board with 3.3V buck converter

Notes / Warnings

• Designed for single-cell lithium batteries only

• Outputs will not exceed 4.5V or 3.3V respectively

• Output voltage may drop to around 3.0V when the battery is nearly depleted

• High input voltage and current may cause heat dissipation

• Solar input works best with 5V to 7V panels

The BQ25185 charger board combines flexible charging options with integrated power regulation, making it a practical solution for portable and solar-powered electronics that require a stable 3.3V supply and efficient battery management.