The USB ports in your vehicle offer more functionality than you might realize, with one of their primary roles being the charging and powering of mobile devices such as smartphones and dash cams. Considering this, you may be questioning whether keeping a USB device connected consistently could lead to a drained car battery. For the majority of contemporary automobiles, there is generally no cause for concern, thanks to a feature called Retained Accessory Power (RAP) in some cars, or simply “delayed accessory power” in others.
The concept of RAP is designed to ensure that certain vehicle systems remain powered after the ignition is turned off, typically for a few minutes. After the designated time has passed, your vehicle’s RAP feature will cut off power to USB ports, car infotainment systems, and other electronic components. However, it’s important to note that RAP is just one instance—many cars automatically shut off power to the USB ports once the vehicle is turned off, even if the owner’s manual doesn’t refer to it as RAP.