A Chinese company has won a politically charged auction for nearly all of A123 Systems Inc., the Waltham batter maker that filed for bankruptcy protection after receiving hundreds of millions of dollars of government support, said an adviser who was present at the auction.

Wanxiang Group, an auto parts conglomerate, outbid Johnson Controls Inc., of Milwaukee, and Japan’s NEC Corp., which had teamed up to bid for A123’s assets, according to the adviser, who was not authorized to speak publicly because the deal has not been finalized.