The time it takes an Android Headunit to load up to the point you can use the Android apps. This is the Android boot time.
Android Boot time is measured in seconds, and while the system is booting, it can’t run any Android apps. You may be able to use the backup camera, but most features will be unavailable until the boot has been completed. This boot happens each time you switch the headunit on, usually, each time you start the car.
Boot time can take several seconds to nearly one minute. The longer the Android system takes to boot, the longer you wait for the maps to become available. It takes seconds to start the engine, but when the seconds are ticking away as you wait for the system to boot can be frustrating. All you want to do is enter the destination, load up a Spotify playlist and start driving, but the clock is still ticking.
Why so slow?
Several main features affect the Android boot speed. These are:
Booting from cold (Cold Boot)
The very first boot of an Android headunit is from cold. This is as if it has only been connected to the power, with no information stored. This is always the slowest way of booting Android. All Android headunits can cold boot or will cold boot. All the information is loaded from scratch with a cold boot, which takes the longest time.
Warm boot (FastBoot)
A warm boot is quicker than a cold boot but can never be the first. A warm boot is set up to store the settings in RAM when the system is powered down. For a warm boot to be successful, the Android headunit needs to ‘sleep’ rather than be switched off. The power to the Android headunit needs to be constant, even when the key is removed from the ignition, for the next boot to be warm. Typically the YELLOW wire is connected directly to the vehicle battery to provide a ‘battery backup’ for sleep mode and warm boot.
Not all Android headunits can FastBoot. This can be a key consideration of the purchase. If you want the system to be available quickly, then a fast boot feature is the only way to get boot time with a fast processor to around 3 seconds.
The Processing power
The faster the processor, the faster the boot. With faster processors comes more RAM, so hand in hand, the faster processor with a good level of RAM (greater than 2Gb) will give a faster boot than a slow processor on the MCU.
The faster 6-core to 10-core processors can cold boot in around an acceptable 10 to 15 seconds.
At best, the slow quad-cores can take over 45 seconds to cold boot.
More apps generally add to boot time, some more significantly than others. This is further impacted on headunits with many apps but limited RAM. Boot time can be almost 60 seconds on a heavily loaded, very slow system.
If you don’t want to wait for your Android headunit to boot up, the quicker headunits with the fastest processors with the fast boot feature can boot in three seconds.
Problems with fastboot can be due to the YELLOW wire causing a drain on a weak car battery. The fast boot can only work if the headunit memory is kept alive with power. Disconnecting the car battery will break the fastboot, and the system will revert to a cold boot for the next startup. Have the car battery checked for deep storage rather than Cold Cranking Capacity.
Fastboot doesn’t work
If you don’t connect the YELLOW wire to the battery (or a permanent live connection), fastboot won’t work, and each boot will be a cold boot. Many vehicles have computer control of the 12v lines, and a direct (fused) connection to the car battery live terminal will bypass any computer intervention.