Hi Jiangxiusi,

Thanks for posting.

Normally the power requirements for Dell computers is between 18-19 volts DC.  If the power converter does not have the correct wattage there could be damages to the system.

Please list the model of your computer and we can find you the correct power converter for you.

Regards,
Robert

Thanks for reply.

I'd like to suggest Dell to develop a kind of new laptop computer whose power input is between 12-48 volts DC. thus ,the computer can use automobile power supply directly