You can charge your scale's battery by plugging the micro-USB cable (or USB-C cable for the Pearl 2021, Lunar 2021, and Pearl S 2022) into any power supply rated with an output of 5 volts and 1 amp.
Pearl 2021, Pearl Model S 2022, and Lunar 2021
The Acaia Pearl 2021, Pearl S 2022, and Lunar 2021 are equipped with charging protection to prevent the battery from charging under high temperatures. It is normal if the scale does not charge when the surface is hot from brewing coffee. The battery charging function will be enabled once the scale has cooled.