ISO 4165

ISO 4165 is a standard adopted by the International Organization for Standardization (ISO) that describes a double-pole DC connector to supply between 12 and 24 V DC at up to 12 amps to appliances in vehicles. Although roughly similar in design to an automotive accessory receptacle, the ISO 4165 connector is shorter and smaller in diameter. It was originally a standard fitting on all the German military vehicles during World War II.

The body (which remains outside the receptacle) is 20 mm in diameter. The resilient neck must mate with a 12 mm diameter hole. The center pin is 5 mm in diameter.

The ISO 4165:2001[1] DC connector is also known as the BMW Accessory plug, as it is used on BMW motorcycles; as the Powerlet connector, named after a firm that produces them; and, in Australia (where they are popular in mobile power applications, including 4WD and Caravaning), as the Hella plug, or Merit plug.

At least one manufacturer sells a plug that combines a cigarette lighter plug and a powerlet, in much the same way that combination auto/airplane notebook computer power adapters combine a cigarette lighter plug and an ARINC 628/EmPower plug.

Four plugs for handlamp sockets (iso 4165) and cigarette-lighter 2
Comparison of (L to R) two Powerlet plugs, one combination plug, and one Cigar Lighter Plug


  • Technical Committee ISO/TC 22, Road vehicles, Subcommittee SC 3, Electrical and electronic equipment


  • ISO 4165:2001 (Second Edition; revisions to the figures and addition of test procedures)
  • ISO 4165:1979 (Original ISO version of standard; withdrawn)
  • BS EN ISO 4165:2003 (British Standard version; current)
  • BS EN 24165:1992 (British Standard version; withdrawn)


  1. ^ "ISO 4165:2001 Road vehicles -- Electrical connections -- Double-pole connection". International Organization for Standardization. 2012-04-20.

See also


Car accessory socket

Car accessory socket may refer to:

Cigarette lighter receptacle

ISO 4165

Cigarette lighter receptacle

The cigarette lighter receptacle (also called a cigar lighter receptacle or cigar lighter socket) in an automobile was initially designed to power an electrically heated cigarette lighter, but became a de facto standard DC connector to supply electrical power for portable accessories used in or near an automobile. While the cigarette lighter receptacle is a common feature of automobiles and trucks, as a DC power connector it has the disadvantages of bulkiness, relatively low current rating, and poor contact reliability.

Examples of devices that can be operated from a cigarette lighter receptacle include lights, fans, beverage heating devices, and small motorized tools such as air compressors for inflating tires. Many portable electronic devices such as music players or mobile telephones use a cigarette lighter receptacle to recharge their internal batteries or to directly operate from the vehicle electrical system. Adapters for electronic devices may change voltage to be compatible with the supplied device. Devices that require alternating-current mains electricity can be operated with a plug-in inverter.

Automobiles may provide several 12 V receptacles that are intended only to operate electrical accessories, and which cannot be used with a cigarette lighter. Car manufacturers may offer a cigarette lighter only as an optional extra-cost accessory. Usually, only one 12 V receptacle near the driver will be able to accommodate an actual cigarette lighter, with other receptacles designated as "12 V auxiliary power outlets" which are not physically able to power a lighter.

DC connector

A DC connector (or DC plug, for one common type of connector) is an electrical connector for supplying direct current (DC) power.

Compared to domestic AC power plugs and sockets, DC connectors have many more standard types that are not interchangeable. The dimensions and arrangement of DC connectors can be chosen to prevent accidental interconnection of incompatible sources and loads. Types vary from small coaxial connectors used to power portable electronic devices from AC adapters, to connectors used for automotive accessories and for battery packs in portable equipment.

List of International Organization for Standardization standards, 1-4999

This is a list of published International Organization for Standardization (ISO) standards and other deliverables. For a complete and up-to-date list of all the ISO standards, see the ISO catalogue.The standards are protected by copyright and most of them must be purchased. However, about 300 of the standards produced by ISO and IEC's Joint Technical Committee 1 (JTC1) have been made freely and publicly available.

ISO standards by standard number

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