The PotatoP is a device focused on maximising battery life. Designed for small programming projects, the PotatoP is slated to deliver up to 2 years of battery life from its 12,000 mAh battery and solar cell.https://www.notebookcheck.net/PotatoP-Low-powered-system-showcases-possibilities-of-laptop-with-years-of-battery-life.701312.0.html
Over a decade ago my modded Kindle 3 let me access bash terminal.
Its battery lasted for about a month. Is it that different?