Keep Your Device Charged
If you want to install the Android Pie update the second it arrives for your device make sure your phone is charged.
Most Android software updates require you to have a 20 percent battery charge to complete the installation process.
We recommend keeping a 50% battery charge on your Galaxy A9, A8, or A7 for Android Pie because it's a huge upgrade and could take a bit of time to finish up.
We also recommend keeping a charger close by. That way, if your phone doesn't have enough charge, you can plug it in to get the installation going right away.