To expand from one to three the number of refundable, $100 million, capital investment Michigan Business Tax credit agreements that could be entered into with makers of plug-in traction battery packs used in electric cars, which were authorized by a 2008 law. That law authorized additional credits for research and development expenses, with total subsidies estimated at $335 million over seven years. This bill would authorize an additional $200 million in subsidies. “Refundable” means that the state will send a manufacturer a check for the amount that the credit exceeds the firm’s tax liability.