Document and Entity Information - USD ($)	12 Months Ended
	Sep. 30, 2016	Dec. 22, 2016	Apr. 02, 2016
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		5,341,993
Entity Public Float			$ 20,910,000
Document Fiscal Year Focus	2016
Document Fiscal Period Focus	FY
Document Type	10-K
Amendment Flag	false
Document Period End Date	Sep. 30, 2016