Automobile auxiliary power outlet (English Wikipedia)

Emadi, Ali (2005-05-25), Handbook of automotive power electronics and motor drives, CRC press, p. 119, ISBN 0-8247-2361-9, The maximum operating voltage for 14 V systems is specified at 24 V, representing a double battery jump-start condition.

cascoglobal.com

"Casco Cigar lighter Facts & Figures". Casco. Archived from the original on 2007-06-25. Retrieved 2007-06-05.^{[dubious – discuss]}

Valdes-Dapena, Peter (2003-11-04). "Cigarette lighters: The new cupholders?". CNN.com. Retrieved 2007-06-05.

GB patent GB189412411A, Friedrich Wilhelm Schindler, "Electric Igniting Device, suitable for Lighting Tobacco-pipes and Cigars.", issued 1895-04-20

Sandoval, David (2010-10-06). "How to Charge a Car Battery Through a Cigarette Lighter". It Still Runs. Retrieved 27 October 2021.

"Double-Battery Jump Start", High-Frequency Automotive Power Supplies, Application note 3893, Maxim Integrated Products, 2007-07-17, Another steady-state OV condition is the double-battery jump start, which occurs when a tow truck or other service personnel use 24 V to jump-start a disabled vehicle or otherwise charge a dead battery. The typical OEM test requirement for this condition is about 24 V for two minutes. Some systems related to safety and engine management are required to operate under these conditions.

"Plugging the cigar lighter gap". Service Management 365. Archived from the original on July 17, 2007. Retrieved 2007-05-30.

"Casco Cigar lighter Facts & Figures". Casco. Archived from the original on 2007-06-25. Retrieved 2007-06-05.^{[dubious – discuss]}
"Plugging the cigar lighter gap". Service Management 365. Archived from the original on July 17, 2007. Retrieved 2007-05-30.