Former General Motors Co. GM, +0.66% Chief Executive Rick Wagoner is back in the car business, taking a seat on the board of a company that makes electric-vehicle charging stations.

Mr. Wagoner has been appointed a director at ChargePoint Inc., a Silicon Valley company that is privately held. He has been advising startup companies since his high-profile exit from GM in 2009, including an electric-vehicle startup that has been working under the radar for nearly a decade.