By Rob Lenihan Lear is working with state and local officials on a plan to open a new manufacturing facility. Before Detroit automakers can switch to making electric vehicles, they have to have the batteries to put into them. So a big announcement Oct. 27 will likely be a key to the transition. Lear Corp. (LEA) – Get Lear Corporation Report will build an $80 million manufacturing plant to supply battery disconnect units for General Motors’ (GM) – Get General Motors Company Report full-size Ultium platform-based electric SUVs and trucks. Lear, which makes automotive seating and electrical distr…