Battery Swell Detection with an Electrically Conductive Dome

A portable electronic device may include a battery assembly and a battery swell detection unit in proximity to the battery assembly. The battery swell detection unit may include an electrode, a dome made of an electrically conductive material positioned between the battery assembly and the electrode, a processor, and memory having programmed instructions that cause the processor, when executed, to detect battery swelling based on a depression of the dome.