Debt (Details) (USD $)	9 Months Ended
	Jun. 29, 2013	Sep. 30, 2012
Debt Instrument [Line Items]
Long-term debt	$ 1,781,000
Current portion of long term debt	1,743,000	43,000
Line of Credit Facility [Line Items]
Debt covenant description	Under the facility, Sevcon USA, Inc. must maintain, on a quarterly basis, a debt to tangible net worth ratio of no more than 2.40:1 and a debt service coverage ratio of no less than 1.25:1 for each rolling twelve-month period.
Total overdraft facility	1,400,000
Overdraft facility, down drawn amount	342,000
Positive bank balance after drawn down facilities	657,000
Annual principal payments on long term debt [Abstract]
2013	10,000
2014	1,743,000
2015	28,000
Total maturities	1,781,000
Secured Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Line of credit facility, amount outstanding	1,700,000
RBS Citizens, National Association [Member] | Secured Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Line of credit facility, maximum borrowing capacity	3,500,000
Line of credit facility, expiration date	Jun. 14, 2014
U.K. bank loan [Member]
Debt Instrument [Line Items]
Long-term debt	81,000
Debt instrument, fixed interest rate (in hundredths)	6.80%
Debt instrument, term	5 years
Debt instrument, periodic payment	4,000
Current portion of long term debt	43,000
Long-term debt, net of current maturities	38,000
Fair market value of the debt	81,000
Annual principal payments on long term debt [Abstract]
Total maturities	$ 81,000