you can buy laptop powerbank with ac output
AC Outlet Portable Laptop Charger, Omars 88Wh/24000mAh 80W AC Power Bank with AC Plug External Battery Pack Laptop Power Bank Portable Power Supply Compatible with MacBook and Devices Under AC 80W
https://www.amazon.com/Portable-Charger-Omars-24000mAh-Compatible/dp/B073P81Z9V