This sentence means that you charge this electric car for 0.5 hours, that is to say, charging for 30 minutes. It should be half an hour is equal to 30 minutes.
Fast charging of new energy vehicles is an emergency charging method, using DC charging, the DC charging voltage is generally greater than the battery voltage, the need to convert alternating current into direct current through the rectifier device, the voltage resistance and protection of the power battery pack put forward higher requirements, the charging current is large, ten times or even dozens of times the conventional charging current. When new energy vehicles use fast charging, it generally takes only half an hour to an hour to charge more than 80% of the electricity. If new energy vehicles often use fast charging, it may slowly reduce the battery capacity and shorten the life of the battery.
It means that the electric charger is fast, and the device can be fully charged in half an hour.