Adafruit 2124 Pro Trinket Li-Ion / Li-Poly Backpack Add-On

The Adafruit Pro Trinket Li-Ion / Li-Poly Backpack Add-On has been cleverly designed to sit on top of the Adafruit Pro Trinket and connect to its power inputs with header pins. Not only does it give you somewhere convenient to connect a battery, it will also charge the battery when the Trinket is powered from its USB port. Once USB power is removed, the fully charged battery will take over. The backpack has a RED charging LED and a green fully charged LED. It uses a 3-stage process, starting with a preconditioning charge, then a constant current fast charge and a final constant voltage trickle charge to keep the battery topped up. By default it uses a 100mA charging current but this can be increased to 500mA by closing a solder jumper for 500mAh or larger batteries. Please only use 3.7 or 4.2V Li-ion or Li-poly batteries, not the older 3.6 or 4.1V types. If you need an On/Off button, carefully cut the marked trace between the pair of solder pads then solder the switch to the pads, nice and easy.

Supplied as a fully assembled and tested charger board plus a strip of 3 x 0.1in. header pins for you to solder between the charger and the Pro Trinket. The battery and breadboard are not included. This tiny add-on board saves you time and effort while greatly extending the use of the Pro Trinket and keeping your project as small as possible.

* Mounts onto a Pro Trinket power lines via a 3-pin header * 3-stage charging process for 3.7 and 4.2V Li-ion and LiPo batteries * Dimensions: 15 x 17 x 2mm (0.6 x 0.7 x 0.08in.) * Adafruit part no.: 2124

Please note that is is perfectly normal for the LEDs to glow faintly when the battery is attached but not charging. This is due to a 0.5mA leakage current from the charger chip's power line.

*Customers looking to resell on eBay or Amazon should contact Adafruit directly.

*Customers looking to resell on eBay or Amazon should contact Adafruit directly.