Charge Your Galaxy Note 9
Once your Android Pie update starts rolling out, make sure you keep your device charged up. This way you'll be able to install the update right when it arrives if that's what you plan to do.
Most Galaxy Android software updates require you to have a 20 percent charge to complete the installation process.
In the case of Android Pie, we recommend keeping a 50% battery charge because it's a huge upgrade and could take 10 minutes, or longer, to complete.
We also recommend keeping a charger close by. That way, if your Note 9 doesn't have enough charge, you can plug it in to get the installation process going.