{"title":"Adafruit Pro Trinket LiIon/LiPoly Backpack Add-On","handle":"adafruit-pro-trinket-liion-lipoly-backpack-add-on","url":"/products/adafruit-pro-trinket-liion-lipoly-backpack-add-on","description":"The Adafruit Pro Trinket LiIon/LiPoly Backpack is a tiny add-on board that sits on top of your Pro Trinket or ItsyBitsy, adding rechargeable LiPo battery support with automatic charging and power switching. When USB is connected, the battery charges automatically. Unplug USB and it seamlessly switches to battery power.\n\nThe backpack is ideal for the 3.3V Pro Trinket and ItsyBitsy boards, where the 3.7–4.2V battery voltage is regulated down to 3.3V. It can also work with 5V boards in many cases, though this runs the microcontroller slightly outside its rated voltage. Charging uses a three-stage process: preconditioning, constant-current fast charge, then constant-voltage trickle charge.\n\nKey Features\n\n\nAutomatic LiPo Charging – Three-stage charging via the Pro Trinket/ItsyBitsy Micro-USB port\n\nAuto Power Switching – Seamless switchover between USB and battery power\n\n100 mA Default Charge Rate – Safe for any battery size; adjustable to 500 mA via solder jumper for batteries 500 mAh and larger\n\nStatus LEDs – Red while charging, green when fully charged\n\nOptional On/Off Switch – Cut a trace and solder in a switch for battery power control\n\nCompact Piggyback Design – Sits directly on top of the Pro Trinket or ItsyBitsy\n\nExtra-Long Header – Allows breadboard use even with the backpack installed; trim for a slim package\n\n\nCompatibility\n\nAdafruit Pro Trinket 3V (recommended)\nAdafruit Pro Trinket 5V\nAdafruit ItsyBitsy boards\nAdafruit LiPo/Li-Ion 3.7V/4.2V batteries only\n\n\nIdeal For\n\nPortable and wearable electronics projects\nBattery-powered sensor stations\nUntethered demonstrations and exhibits\nAny project that needs rechargeable battery support in a compact form factor\n\n\nPackage Contents\n\n1× Adafruit Pro Trinket LiIon/LiPoly Backpack (assembled and tested)\n\n\n\nWarning: For use with Adafruit LiPo/Li-Ion batteries only. Other batteries may have different voltage, chemistry, polarity, or pinout. Battery and Pro Trinket/ItsyBitsy are sold separately.\n","vendor":"Adafruit","product_type":"physical","in_stock":true,"options":[],"variants":[{"id":9060,"title":"Default Title","sku":"AF-2124","price":10.22,"on_sale":false,"in_stock":true,"available_quantity":100,"option1":"Default Title"}]}