Best Buy Capital, the venture capital arm of Best Buy Co., led a $5.5 million Series B round for mobile health and fitness company Valencell. Series A investors TDF and True Ventures also contributed to the round. Valencell has developed earbuds designed to give audio headsets the ability to monitor the health and fitness of the user. The company was formed in 2006 and is based in Raleigh, N.C.

SiBeam Inc., a Sunnyvale, Calif.-based developer of semiconductor systems solutions for wireless communications platforms, has raised an undisclosed amount of strategic funding from Best Buy Capital. The company previously raised over $80 million, from Foundation Capital, New Enterprise Associates, U.S. Venture Partners, Panasonic and Samsung.