Batteries are only covered under warranty for one year and are not covered under the accidental damage protection.


The part numbers for a genuine Lenovo battery (Internal, 3c, 42Wh, LiIon, SMP Rechargeable Batteries , internal):

00HW044, 00HW042, or 00HW043.


Lenovo - https://pcsupport.lenovo.com/us/en/products/laptops-and-netbooks/thinkpad-yoga-series-laptops/thinkpad-yoga-11e-20g8-20ga/20g8/20g8s05t00/parts?linkTrack=Homepage:Body_Search%20Products&searchType=5&keyWordSearch=20G8S05T00


https://lenovo.encompass.com/item/10692645/Lenovo/00HW044/


Newegg  - https://www.newegg.com/Product/ProductList.aspx?Submit=ENE&DEPA=0&Order=BESTMATCH&Description=00HW044&N=-1&isNodeId=1


You may also locate one on eBay or Amazon by searching for it by part number


Example:

eBay for $59.99 - https://www.ebay.com/itm/Genuine-Lenovo-Thinkpad-11e-11e-Yoga-42Wh-Battery-00HW044/173374797814?epid=731714175&hash=item285df177f6:g:by4AAOSwvjBbK-l6:sc:FedExHomeDelivery!36608!US!-1:rk:2:pf:0