Mag safe Power Bank

MagSafe Power Bank — Personal Project (Ongoing)

Siemens NX · KiCAD · GD&T · DFM/DFA · CMF · Electromechanical Integration · Prototype Validation

An individual end-to-end design project — a slim, Qi 2-compatible MagSafe power bank targeting an 18mm profile, designed from enclosure to electronics with consumer feel and manufacturability as primary constraints.

Form factor and tolerance rationale The 18mm thickness wasn't arbitrary — it was derived from a worst-case tolerance stack-up across the slimmest available battery cell, PCB thickness, and enclosure wall clearances. This became the governing constraint for every downstream decision in the enclosure design.

Enclosure design and CMF Designed the housing in Siemens NX applying DFM principles for injection molding — wall thickness uniformity, draft angles, and internal PCB mount geometry. For the housing material, I selected a PC/ABS blend for its thermal resistance and structural strength — critical since the battery generates heat during charging and the user should never feel it. The outer surface uses a 1–2mm acrylic overlay, inspired by the Nothing Phone charger aesthetic — acrylic offers better scratch resistance and a smooth, semi-transparent premium finish that injection-molded plastic alone can't achieve. The trade-off is higher unit cost and longer cycle time, which I documented in a cost-function analysis comparing plastic, aluminum, and acrylic options.

Electronics integration Drafted a custom PCB layout in KiCAD, optimizing component placement, screw boss locations, and thermal clearances to fit within the tight enclosure envelope while maintaining magnetic retention above 1000g and thermal cutoff below 50°C.

Validation Prepared GD&T engineering drawings, BOM, and DFM specifications. Ran early prototype validation across thermal cutoff, magnetic retention, charging efficiency, and battery discharge behavior. Dimensional accuracy verified through stack-up analysis and manual measurement.

Current status: Finalizing PCB layout and material selection ahead of full prototype build.