hiku uses a standard micro-USB connection like the ones found with many popular electronics today for charging. The battery will last 2 months between charges with normal use, so you don’t have to worry about constantly recharging.
For 2nd generation hiku (has 3 small holes where the microphone is, near the charging port):
When hiku is charging, the blue LED near the USB port will blink. When charging is complete, the blue LED will remain solid. Alternatively, you can also check the charge percentage in the hiku app. Please note that a full charge takes about 2 to 3 hours.
If the blue LEDs do not blink when charging, your hiku may need a reset. With the charger plugged in, press and hold the silver button for 20 seconds to reset hiku. You will see the lights blink inside hiku after it resets.