{"title":"Adafruit LiIon or LiPoly Charger BFF Add-On for QT Py","handle":"adafruit-liion-or-lipoly-charger-bff-add-on-for-qt-py","url":"/products/adafruit-liion-or-lipoly-charger-bff-add-on-for-qt-py","description":"The Adafruit LiIon/LiPoly Charger BFF is a compact battery charging add-on designed to mount directly onto the back of any QT Py board. It makes portable power simple — plug in a standard 3.7 V/4.2 V lithium battery, and the charger handles the rest via the QT Py's USB-C connection.\n\nWhen USB is connected, the charger tops up your battery at up to 200 mA (yellow LED indicates charging). When USB is removed, battery power feeds through a Schottky diode to the 5 V rail. A built-in slide switch lets you turn power on and off, and a voltage divider on pin A2 lets your firmware detect whether the board is running from USB or battery.\n\nKey Features\n\n\n200 mA Charge Rate – Charges single-cell 3.7 V/4.2 V LiPo/LiIon batteries via USB-C\n\nAutomatic Power Switching – Schottky diode routes battery power to 5 V rail when USB is disconnected\n\nOn/Off Switch – Built-in slide switch for power control\n\nBattery Monitoring – Voltage divider on A2 pin for detecting USB vs battery power mode\n\nCharging Indicator – Yellow LED lights during active charging\n\nBFF Form Factor – Solders directly onto the back of any QT Py for a compact stack\n\n\nIdeal For\n\nMaking any QT Py project portable with battery power\nWearable electronics requiring rechargeable batteries\nIoT sensor nodes with battery backup\nCompact prototypes needing USB charging capability\n\n\nPackage Contents\n\n1× Adafruit LiIon/LiPoly Charger BFF (assembled and tested)\nHeaders for soldering to QT Py\n\n\n\nWarning: For use with Adafruit LiPo/LiIon batteries only (3.7 V/4.2 V). Do not use with older 3.6 V/4.1 V cells or batteries with different chemistry, polarity, or pinout. Batteries and QT Py board sold separately.\n","vendor":"Adafruit","product_type":"physical","in_stock":true,"options":[],"variants":[{"id":2292,"title":"Default Title","sku":"AF-5397","price":10.22,"on_sale":false,"in_stock":true,"available_quantity":100,"option1":"Default Title"}]}