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Concept hardware

Custom Battery Case

iPhone 12 Pro Max battery case with custom PCB (TPS61090 boost + MCP73831 charger), 2500mAh LiPo, parametric 3D-printed enclosure.

KiCad CadQuery 3D Printing PCB Design LiPo TPS61090 MCP73831

Links

Timeline

Started
Mar 2026
2500mAh
Battery
Custom 4-layer
PCB
Parametric
CAD
MCP73831
Charge IC

Overview

A from-scratch battery case design for the iPhone 12 Pro Max, featuring:

  • Custom PCB — 4-layer board with TPS61090 boost converter (3.7V→5V) and MCP73831 charge controller
  • 2500mAh LiPo — extends phone life by ~60%
  • Parametric 3D enclosure — designed in CadQuery (Python) for easy iteration
  • Two-part sliding design — snap-fit assembly, no screws
  • USB-C passthrough — charge case and phone simultaneously

Full hardware engineering lifecycle: schematic capture → PCB layout → DRC/ERC → 3D modeling → fabrication files.