Hello @Meyer3203 Made with USB 5V TP4056 Lithium Battery Charger Module. $1 ： Parts：M5Stamp C3, Battery, Battery Charger, Diode, Switch, Wire. Work：Connected with double-sided tape. Operation：The RGB LED is lit on the battery. BLOG：M5Stamp C3 and battery https://macsbug.wordpress.com/2022/01/26/m5stamp-c3-and-battery/