I was gifted an Epson HX-20 early in the 80's. Considered the first laptop computer released. It had battery life of 30-40 hours! Basic, Contacts, Spreadsheet, Terminal, and Word Processor built into it. Offering a generous 16kb or optional 32kb of RAM in addition to a built in micro cassette storage; it was ahead of anything ever offered.

The famous Tandy 100 (and WP-2) series laptops were based off this design.

As I was young I didn't understand the full capacity of the device. However when Tandy released the WP-2 portable word processing device (battery life of 40 hours; 4 AA's). I snatched it up in an instant.

Here's more on all three devices:

https://en.wikipedia.org/wiki/Epson_HX-20

https://obsoletecomputermuseum.org/model100/

https://obsoletecomputermuseum.org/wp-2/