Charge Your Galaxy S9
Once your Galaxy S9 Android Pie update starts rolling out, make sure you keep your phone charged. This way, you'll be able to install the update when it arrives.
Most Galaxy Android software updates require you to have 20 percent battery charge to complete the installation process.
We recommend keeping a 50% battery charge for Android Pie because it's a huge upgrade and could take quite a bit of time to complete.
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 Android Pie upgrade process rolling right away.