The car cigarette lighter socket or car adapter that most automobile drivers and passengers are familiar with is properly called a cigar lighter receptacle, since it was originally designed as a lighter for cigars.
These sockets were not originally designed to provide electrical power, and are not an ideal power connector for several reasons, notably the fact that three sizes exist (two for 12-volt DC and one for the older 6-volt DC systems) and the mating of the different sized 12 V DC plugs and jacks is problematic. Because of this, and the small-gauge wiring sometimes used, the power connections they provide are sometimes unreliable and not suitable for high-power devices.
Despite these limitations, they are often used for powering or recharging many devices; for example, electric razors, portable spotlights, laptop computers, mobile phones, PDAs, USB adapters, digital audio players, lamps, or even thermoelectric coolers. For devices that run on regular AC line voltage, a plug-in inverter is used to convert to alternating current, and transform it up to 120 or 240 volts AC. Inverters have become so popular that some larger vehicles (minivans, pickup trucks, SUVs, and especially recreational vehicles) come with them built-in, along with domestic AC sockets.
Heavy power drains with the vehicle's engine switched off may be harmful to standard lead-acid car batteries which are not designed for "deep cycle" power drains; thus highly-specified recreational vehicles (and also boats) will often feature a secondary, deep-cycle "leisure battery", specifically designed for this purpose.
Universal ones have a switch that allows selection of 3, 4.5, 6, 9, and 12 volts. Some instead supply 5 volts to a USB "A" socket, allowing USB devices to be powered or recharged.Car battery charger is suitable for travel, because it is an auto charger, portable and cheap. |
