Panasonic, the exclusive battery cell supplier for Tesla Inc's current production models, could reduce its heavy reliance on the U.S. EV maker whose production delays previously weighed on the Japanese company's earnings. Panasonic is set to lose its exclusivity as Tesla plans to source cell production locally at a new auto plant in Shanghai, "most likely from several companies" including Panasonic, Elon Musk, Tesla chief executive, tweeted in November. Under the planned joint venture, Panasonic would shift most of its prismatic battery-related equipment and facilities in Japan and China to the joint venture, while those producing batteries for Tesla will remain under the company. Panasonic already makes prismatic batteries for Toyota, whereas for Tesla it makes cylindrical batteries of a type similar to those used in laptops. It's not clear yet how Panasonic would supply its prismatic batteries to other automotive clients, which include Honda Motor and Ford Motor.