Nokia encountered a problem in mid-2007 when 46 million BL-5C batteries supplied by Matsushita and installed in Nokia phones were found to be defective, causing overheating and explosion issues. Nokia addressed the issue by setting up a website and call center for users to check if their battery was defective and replacing defective batteries free of charge through their customer care centers. However, the battery issues caused a temporary setback in Nokia's market performance, with a decrease in market share and failure of new phone models, resulting in Nokia losing its top position in the global mobile phone market.