How many docker images can I store in Docker Private Repository

I have created one private repository in docker hub.
My doubts are

1. How many separate images can I store in my single private repository?
   
2. Is there any image size restriction?
   
3. When do I need more than one private repository?

Best practice is to use one repository per application. You use different tags to differentiate between versions and flavors of your app. Theoretically you can mix totally different Docker images in one repo. But maybe you can just choose a different Docker repository provider instead that offers more private repositories for free like Codefresh, GitLab and some others.