A 'Yes' answer indicates that the CPAP Machine has an optional DC cable that plugs directly into a DC port. This allows you to use a DC power source, such as a battery or car cigarette lighter outlet. Some optional DC cables include alligator clips to connect directly to battery terminals. See the "Power" tab of the machine's product page for more detailed information on how the machine works with alternate power sources, and what optional cables and batteries are compatible.