The Adafruit bq25185 Charger is a versatile LiPo/LiIon/LiFePO4 charging board that supports USB, DC, and solar power input. It is an excellent upgrade from MCP73833 or MCP73831-based chargers, offering multi-chemistry support, adjustable charge rates, smart power path management, and near-MPPT solar optimisation.

Connect your battery to the JST PH 2-pin port, charge via USB-C or DC/solar input, and draw power from the regulated load output (up to 4.5V max). The smart power path prioritises external power while sending excess current to the battery, extending battery life and allowing up to 3A current spikes from battery to load.

Key Features

• USB Type-C Input – 5V at up to 1A with 5.1k CC resistors for universal compatibility
• DC/Solar Input – 5–18V via side pads with near-MPPT solar optimisation
• Adjustable Charge Rate – 1A (default), 500 mA, or 250 mA via onboard jumpers
• Multi-Chemistry Support – LiPo/LiIon (4.2V max) or LiFePO4 (3.65V max) via jumper selection
• Smart Power Path – Prioritises external power with up to 3A battery-to-load spikes
• Regulated Load Output – Up to 4.5V max (ranges from 3.0V at low battery to 4.5V with external power)
• Thermistor Support – Cut the TH trace and add a 10K thermistor for temperature-based charge regulation
• Chip Enable Pin – Disable the charger when needed
• Mounting Holes – For secure installation

Status LEDs

• Orange – Charging
• Red – Fault
• Green – Power good

Also Available

• bq25185 with 3.3V Buck Board – Same charger with integrated 3.3V regulated output
• bq25185 with 5V Boost Board – Same charger with integrated 5V regulated output

Ideal For

• Portable battery-powered projects with custom voltage regulation
• Solar-powered IoT devices
• LiFePO4 battery projects requiring adjustable chemistry settings
• Replacing MCP73833/MCP73831 charger setups

Package Contents

• 1× Adafruit bq25185 USB/DC/Solar Lithium Ion/Polymer Charger Board