Summary

Hello! I made mini-voltmeter. It's easy!

Warning! Only 0-100v
Tp4056: https://aliexpress.ru/item/32649780468.html?sku_id=66766304851&spm=a2g2w.productlist.search_results.1.3c315eefCEf6MP

Good 18650: https://aliexpress.ru/item/32807032859.html?sku_id=12000027820587062&spm=a2g2w.productlist.search_results.0.6b4b23a9AvxGZm

Holder for 18650: https://aliexpress.ru/item/4000859859685.html?sku_id=10000009684900416&spm=a2g2w.productlist.search_results.3.6e49395dN6T4sD

On-off toggle switch(button): https://aliexpress.ru/item/1005004551528434.html?sku_id=12000029579960485&spm=a2g2w.productlist.search_results.11.7fdc53c9tHZyVa

Voltmeter: https://aliexpress.ru/item/4000109042236.html?spm=a2g2w.orderdetail.0.0.1bff4aa6cffirD&sku_id=12000035367370503

You need a delete banana connectors
Wires: https://aliexpress.ru/item/32879671739.html?sku_id=65579353023&spm=a2g2w.productlist.search_results.3.6c1f500e3slnrq