https://www.theverge.com/2023/1/5/23541379/lenovo-thinkbook-... says: "Just don’t expect Kindle battery life out of a laptop like this since you’ve got the overhead of running Windows on its 13th Gen Intel processor (and up to 16GB of RAM and 1TB of PCIe Gen 4 storage) rather than a simple e-reader chip. Lenovo’s estimating up to 21 hours of battery life from its 56Wh battery using the E Ink screen, and it isn’t providing context about what kind of content can run for 21 hours at a time."