Automobile auxiliary power outlet

Such include mobile phone chargers, cooling fans, portable fridges, electric air pumps, and power inverters.

[3] In the 1890s, these tools were sold as electrical cigar lighters (Cigarrenanzünder, later Zigarrenanzünder) in the major German warehouse catalogues.

[4] The modern "automatic" removable automotive V-Coil lighter was developed by Casco in 1956,[6] for which it received U.S. patent 2,959,664, issued in 1960.

UL2089 was developed to cover the requirements for portable adapters rated 24 V DC or less that are intended to be supplied from the battery powered electrical system of a vehicle.

[8] The heating element glows orange hot in seconds, causing the bimetallic strip to bend and release the mechanism.

The advantage of such a design is in safety as the red-hot heating element cannot be accidentally dropped onto an occupant's lap.

Still, it takes away the ability for the lighter to be removed for the receptacle to be used as a power outlet, and it also does not allow cigars to be lit as the opening is not large enough.

These outlets usually have a plastic cap tethered to them, and are usually labeled as being only for DC power, because they are not intended to withstand the heat produced by an electrical cigarette lighter.

The use of cigarette lighter receptacles to supply 12 volt DC power is an example of backward compatibility to a de facto standard.

Portable cigarette lighter receptacles attached to cables and alligator clips for connection directly to car batteries are available for temporary use.

Plus in newer cars, the power output from the lighter plug is so reliable that it can charge laptops, without any voltage problems.

In addition to the issues with partially-compatible physical dimensions, the plugs can vibrate out of the socket under normal driving conditions, owing to poor retention.

Also, there have been reports of melted plug tips due to poor contact and heat generation from ohmic resistance.

[16] Robust equipment must tolerate temperatures varying between −40 and +85 °C (−40 and 185 °F), plus possible high humidity and condensation of water.