The Adafruit bq25185 is an all-in-one charging and power supply board that supports USB, DC, and solar charging with an integrated 3.3V buck converter. It is an excellent upgrade from MCP73833 or MCP73831-based chargers, combining power path management and regulated output in a single board.

Connect a 500 mAh or larger LiPo battery to the JST PH 2-pin port, charge via USB-C or DC/solar input, and power your 3.3V project directly from the regulated output. Smart power path management prioritises external power, sending excess current to the battery instead of constantly cycling it.

Key Features

• USB Type-C Input – 5V at up to 1A with 5.1k CC resistors for universal compatibility; data lines broken out on the bottom
• DC/Solar Input – 5–18V via side pads with near-MPPT solar optimisation
• Adjustable Charge Rate – Defaults to 1A, adjustable to 500 mA via onboard jumper
• Smart Power Path – Prioritises external power, extends battery life by avoiding charge cycling
• 3.3V Regulated Output – TPS62569 buck converter delivering stable 3.3V at up to 1A
• 4.5V Max Load Output – Ranges from 3.0V (low battery) to 4.5V (external power active) at up to 1A

Status LEDs

• Orange – Charging
• Red – Fault
• Green – 3.3V output active

Additional Features

• Enable Pad – Disable the 3.3V buck converter when not needed
• Battery Monitoring Pads – Check battery voltage via breakout pads on the bottom
• Mounting Holes – For easy installation in enclosures

Ideal For

• Portable 3.3V battery-powered projects
• Solar-powered IoT devices
• Projects requiring USB + solar charging flexibility
• Replacing MCP73833/MCP73831 charger setups with integrated power regulation

Package Contents

• 1× Adafruit bq25185 USB/DC/Solar Charger with 3.3V Buck Board