CarPlay causes battery drain on all iPhones
I have never had battery problems with my iPhone until I purchased a new vehicle with CarPlay just over a week ago.
After pairing my phone with the car for CarPlay, I have had battery problems ever since and dead flat battery twice, by just leaving the phone off charge overnight!
I disabled Bluetooth and the problem went away, then I removed my vehicle from the CarPlay settings in my iPhone SE, enabling BlueTooth again and ensuring the phone was fully charged to 100%,
I checked the phone this morning and voila, battery level with Bluetooth on is 100% instead of 33% or less overnight!
I think that we can safely say that CarPlay does not time out when searching for the vehicle and is causing the battery problems!
This will answer the question for many people with battery problems that have CarPlay....
People can test this by simply charging your phone to 100%, turning off Bluetooth overnight and check the battery level in the morning.
Secondly, re-enable Bluetooth and remove your vehicle from the CarPlay settings in your phone.
Charge your phone to 100% and check your battery level again, in the morning.
At least people can manage this issue until Apple issues a fix by turning off Bluetooth at night or remove the vehicle from the CarPlay settings!
iPhone SE, iOS 11.4