How to Make a 9V Rechargeable Lithium ion Battery DIY

Hi, everybody These days, this is rare, but still some devices are equipped with 9-volt batteries. The problem is that they are constantly discharged, and if they are changed every time, it is expensive. So I decided to make a 9-volt battery myself and charge it if necessary. Here are the links to the components from the video: 1. DC-DC converter - http://alli.pub/6ew9nt 2. Charging board with double protection function -http://alli.pub/6ew9sa 3.I found the battery in my stocks, if you don't have one, then this battery will be perfect for you (you can put 2 pieces in parallel) http://alli.pub/6ew9um