GM recently showed a slide that said that its lithium-ion battery costs are down to about $145 per kilowatt hour, Hybrid Cars says, citing comments General Motors made at its Global Business Conference in Michigan. The company also showed that these costs may drop to $100/kWh by 2021. Heady stuff considering that Tesla Motors has said it’d hit those cost levels in 2020, and Tesla is not outsourcing the job like GM is (LG Chem makes the cells for the 2015 Spark EV and the Chevy Volts) . General Motors representatives confirmed to Autoblog that GM executive Mark Reuss presented the battery-cost estimate slide in a presentation at the conference.