Slicers (applies to each fact value in each table cell)

Reporting Entity [Axis]	0001167178 (http://www.sec.gov/CIK)
Statement, Scenario [Axis]	Scenario, Unspecified [Domain]

Statement	Period [Axis]
	2011-12-31	2010-12-31	2009-12-31	2008-12-31
ASSETS
Current assets:
Cash and cash equivalents	186,893,000	216,841,000	457,122,000	70,510,000
Restricted cash and cash equivalents	668,000	9,367,000
Accounts receivable, net	47,200,000	28,106,000
Inventory	103,394,000	47,765,000
Deferred cost	6,256,000	1,022,000
Prepaid expenses and other current assets	8,011,000	8,006,000
Total current assets	352,422,000	311,107,000
Property, plant and equipment, net	145,203,000	143,998,000
Goodwill	9,581,000	9,581,000
Intangible assets, net		413,000
Long-term grants receivable	101,054,000	75,790,000
Deposits and other assets	5,745,000	11,768,000
Restricted cash and cash equivalents, net of current portion		1,993,000
Investments	11,897,000	21,508,000
Total assets	625,902,000	576,158,000
LIABILITIES AND STOCKHOLDERS' EQUITY
Current liabilities:
Revolving credit lines	38,094,000	8,000,000
Current portion of long-term debt	2,069,000	5,379,000
Current portion of capital lease obligations	1,740,000	1,571,000
Accounts payable	27,220,000	43,523,000
Accrued expenses	31,910,000	48,179,000
Other current liabilities	8,329,000	7,550,000
Deferred revenue	9,577,000	4,881,000
Deferred rent	181,000	132,000
Total current liabilities	119,120,000	119,215,000
Long-term debt, net of current portion	142,755,000	4,603,000
Capital lease obligations, net of current portion	17,336,000	18,655,000
Deferred revenue, net of current portion	35,303,000	29,836,000
Deferred rent, net of current portion	1,203,000	1,452,000
Other long-term liabilities	13,820,000	3,865,000
Total liabilities	329,537,000	177,626,000
Commitments and contingencies (Note 10)	xsi:nil	xsi:nil
Stockholders' equity:
Preferred stock, $0.001 par value-5,000,000 shares authorized; 0 shares issued and outstanding at December 31, 2010 and December 31, 2011	xsi:nil	xsi:nil
Common stock, $0.001 par value-250,000,000 shares authorized; 105,194,073 and 134,342,974 shares issued and outstanding at December 31, 2010 and December 31, 2011, respectively	134,000	105,000
Additional paid-in capital	946,506,000	790,256,000
Accumulated deficit	(648,958,000)	(391,228,000)
Accumulated other comprehensive loss	(1,317,000)	(935,000)
Total A123 Systems, Inc. stockholders' equity	296,365,000	398,198,000
Noncontrolling interest		334,000
Total stockholders' equity	296,365,000	398,532,000
Total liabilities and stockholders' equity	625,902,000	576,158,000