【4000mAh Ultra Large Capacity Wireless Charging Case】The wireless charging case is equipped with built-in 4000 mAh battery which, It has enough battery to charge the earbuds several times, one full charge will deliver 4-6 hours listening time, gives up to 220 hours of continuous standby time.
https://www.amazon.com/LiyuanQ-Wireless-Charging-Bluetooth-Capacity/dp/B08B3ZTYHQ