ECOtality Inc., an Energy Department-backed maker of electric car charging systems, is facing a major cash crunch and could file for bankruptcy.

The company, which has been awarded nearly $100 million in grant funding under the 2009 stimulus law, disclosed Monday that it’s weighing a restructuring or sale as it seeks more outside capital.

ECOtality, in a Securities and Exchange Commission filing, listed several “adverse developments” that together “significantly impact its ability to meet its ongoing obligations and to fund anticipated operating losses.”

The woes of the company, one of several backed by the Energy Department to face financial problems or bankruptcy, are sure to renew criticism of federal green-tech loan guarantee and grant programs.