Ford Motor is moving forward on construction of a battery plant in Michigan but at a reduced size from original plans, citing a pullback in the outlook for future electric-vehicle demand. Ford in September paused work on the factory, in Marshall, Mich. At the time, the company said it was reassessing its ability to competitively operate the plant, which will make batteries using technology from China’s Contemporary Amperex Technology Co. On Tuesday, Ford said it has resumed work at the site, but downsized the scope of the project, with plans to produce roughly 40% fewer batteries than originally planned.