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

Power your portable projects with ease using this smart USB/DC/Solar LiPo Charger (Adafruit PID 6092). Built around the TI bq25185 charging IC, it supports charging from USB‑C or a 5–18 V DC/solar source. Thanks to the integrated power path, you can safely charge the battery and power your circuit at the same time — no extra switching required.

Importantly, the board features 5.1 k pull-up resistors on the USB‑C CC lines, ensuring correct negotiation as a standard 5 V device. This prevents the charger from accidentally requesting higher voltages, making it ideal for use with power banks and USB‑C wall adapters.

The integrated 3.3 V buck converter (TPS62569) delivers a stable 1 A output, perfect for powering microcontrollers, sensors, and other 3.3 V components. Convenient status LEDs provide clear feedback on charging, battery status, fault conditions, and 3.3 V output activity. A single-cell LiPo battery connects easily via the JST‑PH connector.

Whether you’re building an IoT device, solar-powered project, or portable field system — this board provides safe, efficient charging and reliable power delivery.

Key Features

• Power path charging: USB‑C or 5–18 V DC/solar input with automatic switching
• 5.1 k pull-up resistors on CC lines — ensures safe 5 V negotiation on USB‑C
• 1 A charging current (configurable to 500 mA via jumper)
• Integrated 3.3 V buck converter up to 1 A, parallel with max. 4.5 V power path output
• Status LEDs: charging, battery status, fault, 3.3 V active
• Compact size: only 30 × 19 × 10 mm, easy to integrate

Technical Specifications

• Charging IC: TI bq25185
• Buck converter: TPS62569, 3.3 V/1 A
• Inputs: USB‑C (5–20 V), or 5–18 V via solder pads
• CC resistors: 5.1 k pull-ups to GND (standard 5 V detection on USB‑C)
• Battery connection: single-cell LiPo via JST-PH (minimum 500 mAh recommended)
• Outputs:
• Power path: 3.0–4.5 V up to 1 A
• Regulated 3.3 V up to 1 A
• Charging current: default 1 A (jumper configurable to 500 mA)
• PCB dimensions: 30.2 × 19.0 × 10.0 mm
• Protections: overvoltage, short circuit, thermal protection
• Applications: portable electronics, IoT projects, solar-powered systems, low-power embedded designs