Document and Entity Information
6 Months Ended
Mar. 31, 2011
May 11, 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 Common Stock, Shares Outstanding   3,485,322
Document Fiscal Year Focus 2012  
Document Fiscal Period Focus Q2  
Document Type 10-Q  
Amendment Flag false  
Document Period End Date Mar. 31, 2012