Raspberry Pi Zero 2 W with Ubuntu Server 21.10 support is here | Ubuntu
Pisugar Portable 900 mAh /1200 mAh Lithium Battery Power Module for Raspberry Pi-Zero, Pi-Zero W/WH Model Accessories (Not Include Raspberry Pi) (1200 mAh) : Amazon.in: Computers & Accessories
Finally, an easy way to power the Pi Zero with a battery : r/raspberry_pi
Sleepy Pi 2 (Power Management Shield for Raspberry Pi)
Online calculators that are handy for EEs
Build Your Own Raspberry Pi Weather Station with IntialState