To solder rechargeable batteries, the case of which is made of stainless steel, a conventional soldering flux will not help here - you need to use zinc chloride. It will also be necessary to use a thin copper wire (however, it must first be tinned).
In principle, there is nothing complicated in soldering stainless steel batteries, the main thing is simply to follow the technology for performing this procedure and not overheat the case itself with a soldering iron, otherwise the battery may be covered with a "copper basin".
The main stages of work
First of all, we apply one drop of zinc chloride to the back of the battery, after which we attach a copper wire to the soldering point with solder at the end, press firmly and heat it with a soldering iron. It is not necessary to hold the soldering iron for a long time so as not to overheat the case - just a few fractions of a second is enough.
A similar operation is performed on the other side of the battery. After this place of soldering, it is necessary to moisten it with hot water, and then wipe it with alcohol, since chlorine oxidizes very quickly.
By the way, there is another easy way to solder stainless steel. Instead of zinc chloride, you can also solder stainless steel batteries with phosphoric acid - in this case, the solder spots are washed with a soda solution.
After such a simple procedure, the batteries can be soldered to the board without any problems. For more information on how to solder rechargeable stainless steel “banks”, see the video on the website.
