Lithium Battery Level Indicator Module 1S Single 3.7V Capacity by Indian Hobby Center : Amazon.in: Electronics
Battery Level Indicator Circuit using LM3914
Diy Lm3914 Power Indicator General 12v Battery 3.7v Lithium Battery Power Level Led Indicating Measurement Display Board Tester - El Products - AliExpress
Simple Battery Level Indicator Circuit using Op-amp