An auto DC adapter has a cigarette lighter input plug on one end that is plugged into the cigarette lighter receptacle and on the other a special output connector that is plugged into the laptop's power receptacle. Although recent P4 laptops have higher and higher power requirements, auto batteries have the capacity to supply the necessary output for the PC.

KOHJINSHA
     Kohjinsha SA Series
        SA1F0, SA1F00A, SA1F00B,
        SA1F00D, SA5SKX08AL, SA5SKX08FL,
        SA5SX04A, SA5SX12A, SA5SX12F

     Kohjinsha SC Series
        SC3KB06GH, SC3KP06A, SC3KP06F,
        SC3KP06GA, SC3WP06A, SC3WP06F,
        SC3WP06GA

     Kohjinsha SH Series
        SH6KR12A, SH6KX04A, SH6WB04A,
        SH6WX04A, SH6WX12A, SH8KP12A,
        SH8KP12F, SH8KPS3ABX1, SH8KPS3FBX1,
        SH8WP12A, SH8WP12F, SH8WPS3ABX1,
        SH8WPS3FBX1

     Kohjinsha SR Series
        SR8KP06A, SR8KP06F, SR8KP12A,
        SR8KP12F, SR8WP06A, SR8WP06F

     Kohjinsha SX Series
        SX3KB06MH, SX3KP06MA, SX3KP06MF,
        SX3KX06MA, SX3KX06MF, SX3WP06MA,
        SX3WP06MF, SX3WX06MA, SX3WX06MF