sk innovation cos shares slumped wednesday after ford motor co a partner of the companys batterymaking subsidiary halted production and shipments of its electric pickup truck over a potential battery issue the south korean energy company is the parent of sk on co which supplies batteries for fords f150 lightning a topselling ev pickup in america shares of sk innovation fell as much as 78 to 154400 won 12133 in morning trade staying on course to post their sharpest daily percentage drop in 19 months the stock underperformed the benchmark kospis 12 fall the decline comes after ford said that it has halted production and shipments of the f150 lightning to investigate a potential problem with the trucks batteries the us auto maker said its detroitarea factory where the model is built has been idle since the start of last week sk on which runs a battery plant in georgia has supplied ev battery cells for the f150 lightning since early 2022 according to sk innovation sk innovation said in a previous news release posted at its website that sk on is producing ncm9 battery cells at the georgia plant for ford ford began producing the f150 lightning in april before the output halt it had ramped up production to meet what it says is a long customer wait list