To what extent is this a working version of altering the power supply of a screwdriver to 18650?

Question

Batteries

I want to replace the battery (12V 1.2Ah) in a screwdriver with a replaceable 18650.
There are many different conversion schemes on the Internet, but they are all rather complicated. I would like an easier option. As far as I understand, such a box is enough for me (three 18650 in series) - www.aliexpress.com/item/16850-Battery-Case-Storage...
and such a board (protective board for 3s 18650) - www.aliexpress.com /item/New-Arrival-Best-Price-3S-...
I will charge in a separate charge, so I don’t seem to need any balancers, charge indicators and other stray.

Answer 1

I myself want to do the same, I did not find a charger for individual elements.
I wanted to stick 3 elements instead of 10 dead Nickel-Cadmium.
Now - a 7Ah battery from an uninterruptible power supply is attached to the wire - enough for a working day ...
And what is the point of a protective board? She is like a charge, judging by the Chinese translation.

Answer 2

mysku.ru/blog/aliexpress/28764.html
https://www.drive2.ru/b/2336972/
roboforum.ru/forum61/topic12163.html
here are the links offhand. read and do.