The power supply manufacturer has raised further funding from existing investors including DoCoMo.

US-based mobile device battery manufacturer Quantance secured $11m of series C funding on 26th September from DoCoMo Capital, the corporate venturing unit belonging to Japan-based mobile communication company DoCoMo, and venture capital (VC) firms TD Fund, Granite Ventures and InterWest Partners.

Quantance’s series B round raised $12m from the same investors, in November 2008, while Granite, InterWest and VC firm CampVentures were the backers for Quantance’s $7m September 2006 series A round.

Quantance manufactures batteries for 4G wireless mobile devices,…