To start off, thanks to JLCPCB for sponsoring this project as well as providing pcbs to get the ball rolling. JLCPCB Prototype for $2 (Any Color): https://jlcpcb.com
After fixing my two beautiful Sony Discman players the next natural progression was making rechargeable batteries for them since oem ones are difficult to find, expensive, and barely work given that they are nearly 30 years past their prime. Requirements for the design include: usb rechargeable, higher capacity than the originals (850mAh vs 550mAh!), easily/cheaply 3D printed, and drop in replacement. So let's get to work seeing what I came up with and the design iteration process.
The parts are all cheap and widely available, consisting of a usb lipo charger board (my affiliate link: https://ebay.to/2DnGEj4), an ipod video battery (https://ebay.to/2KSoYlN), and finally a simple tiny metal contact pcb (board files will be released shortly). All that is necessary to wire everything is to attach positive of the three parts together and attach negative together, it is that simple. Physical construction is just a matter of hot gluing the components into the plastic 3d printed shell (stl files will be released shortly) and gluing or taping it all shut. Printing the case takes around 45 minutes, and assembly should take no more than half an hour.