Shaky Battery Maker Claims a Breakthrough.

DETROIT -- Lauded during a visit by President Obama, A123 Systems was supposed to be a centerpiece of his administration's effort to use $2 billion in government subsidies to jump-start production of sophisticated electric batteries in the United States. Instead, the company, which makes lithium-ion batteries for electric cars, has stumbled along with the rest of the nascent industry and now threatens to give more ammunition to critics of the president's heavy spending on new energy technologies. [ABSTRACT FROM AUTHOR]