Document and Entity Information (USD $)
12 Months Ended
Sep. 30, 2012
Dec. 05, 2012
Mar. 31, 2012
Document and Entity Information [Abstract]      
Entity Registrant Name SEVCON, INC.    
Entity Central Index Key 0000825411    
Current Fiscal Year End Date --09-30    
Entity Well-known Seasoned Issuer No    
Entity Voluntary Filers No    
Entity Current Reporting Status Yes    
Entity Filer Category Smaller Reporting Company    
Entity Public Float     $ 17,380,000
Entity Common Stock, Shares Outstanding   3,475,306  
Document Fiscal Year Focus 2012    
Document Fiscal Period Focus FY    
Document Type 10-K    
Amendment Flag false    
Document Period End Date Sep. 30, 2012