Get a Fairphone, the batteries in those are removable and I’m pretty sure you can run them while battery is disconnected and plugged in.

Even if not, the replacement batteries are very cheap. I think about 25 in whatever currency.

https://www.fairphone.com/en/

If you’re open to trying fantasy (not far off from sci-fi), the Redwall series might be of interest.

Although it was originally aimed at young teens, it’s a very enjoyable series for adults too. Some of the best writing I have ever come across.

Good luck with your search!