Battery maker Exide Technologies yesterday filed for US Chapter 11 bankruptcy protection, blaming a heavy debt load from its acquisitions and price competition in the vehicle supply market, the Financial Times reported. The FT said that Exide had tried to survive federal bribery charges and a guilty plea bargain but said debt and integration costs from mergers had overwhelmed it. Exide has been in violation of bank financing covenants since last Friday and had a $US15 million bond payment due on Monday, the paper added.