Yesterday such a scarf arrived. tested by charging one jar with a current of 1A and an incoming 12V.
I bought a weak protection board, 20A. It works perfectly, the choke and the microcircuit are a little warm, by 45 degrees. I had to buy more powerful. Now I have another helper 🙂
And repack Addendum: this was all done about a month ago.
Etched and unsoldered the board, installed everything in the case.
More than 15 years ago, I brought my father a Black screwdriver from the USA as a gift
The transistor heats up, holding a finger is a little uncomfortable. But for Shurik at 6 volts – and this is a very good result.
In my https://jiji.com.gh/43-self-contain-for-sale/2-bedrooms alteration, I implemented the correct battery charging, charge indication and smooth adjustment. If the cartridge is not strongly clamped by hand, the battery is chopped off. I made a timer for the charge indicator. I can recommend it to Now it glows for about a minute after the button is released.
Now it turns off if you strongly hold the cartridge.
Timer:

Another conversion of the screwdriver to lithium, with the correct battery charging.

There are many articles on this topic on the site. Offline I bought a 12 volt unit for charging.