CAUTION: Before starting this guide, make sure that the batteries are fully drained (0%)

We are using old batteries from the iPhone 7 Plus and iPhone 8 Plus. Peel off the tape on the battery protector off with tweezers.

Please use non-conductive tweezers to avoid short-circuiting the battery.

Apply tin to the anode and cathode of the battery with a soldering iron at 365°C. Heat to remove the protection board.