There are two working modes of CK310 - wireless mode and wired mode.
With charging wire, connect CK310 to your existing car charger using the USB cable provided, CK310 will automatically power on once the car ignition starts and automatically power off once the car engine is turned off. Also you don't have to worry about the battery in this mode.
Without charging wire, CK310 will not automatically turn on / off with the car engine. You have to manually turn it on every time you get into your car and it will auto turn off in 5 minutes when disconnected from your phone or turn off in 15 minutes if out of range. Pay attention that the build-in battery of CK310 has 7 hours of talk time and 12 hours of standby time, please charge in time or it will be powered off due to low battery.