The problem is that a lot of the chargers are not a good fit in the 12V cigar lighter plug. Unfortunately there are two standards for cigar lighter plugs, this often means poor connections. Naturally they were never really intended to be used as power sources. A decent USB socket will always give a good connection.

Originally Posted By Wikipedia
12-volt cigar lighter receptacle and plug, size A

Receptacle inside diameter: 20.93 - 21.01 mm (median 20.97 mm)
Plug body diameter: 20.73 - 20.88 mm (median 20.805 mm)
Most often used in American automobiles.

12-volt cigar lighter receptacle and plug, size B

Receptacle inside diameter: 21.41 - 21.51 mm (median 21.455 mm)
Plug body diameter: 21.13 - 21.33 mm (median 21.18 mm)
Most often used in European automobiles, and sometimes as a second socket in American automobiles expressly for DC power connections.


For more information see http://en.wikipedia.org/wiki/Cigarette_lighter_receptacle

A better plug for power applications and charging is the ISO 4165 connector but it is more difficult to find adaptors for this type of socket.

Last edited by Gambalunga; 01/02/14 10:36 AM.
Peter

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