The Adafruit Feather series has a built-in battery charger with the microUSB port. However, it only has a charging rate of 100mAh – That means it would take 44 hours to fully recharge a 4400mAh battery!
For a faster charge, we recommend using the Adafruit Micro-Lipo Charger – This has a charging rate of 500mAh (0.5A jumper must be soldered) so it only takes 8 hours to fully recharge a 4400mAh battery.
The Adafruit Feather and Prop-Maker FeatherWing are accessible by unscrewing the blade emitter. Use the microUSB breakout extension to update code, flash new firmware or recharge the battery (although slowly!). Depending on how the Feather and FeatherWing are oriented, the opening in the hilt allows access to the RESET button, audio volume trim pot, and JST connectors for the speaker and battery.