Here is what I learnt recently. OneNote can affect battery power consumption. You can improve battery life by changing a simple setting.
Improve battery life – setting in OneNote
Go to File – Options – Advanced. Scroll down to Battery Options.
Choose Maximum Battery Life from the dropdown. That’s it.
While we are at it, might as well save some disk-space. Go to File – Options – Save and Backup section. Change the backup copies from 2 (which is the default) to 1. Nowadays, all the notebooks I create are stored in OneDrive. In that case, we don’t really need a local backup. Therefore, I chose to store no backup at all. But it is your personal choice.
By the same logic, I have also disabled the backup of notebooks which are stored in SharePoint (which also includes OneDrive).