Q: Why will my Ipad not backup when I had lots of Storage available?

HI Ken,

Welcome to Apple Support Communities.

It sounds like there's an issue backing up your iPad to iCloud, you're seeing an alert that says there isn't enough storage. The article below describes that alert message and it provides tips that should help you resolve the issue. 

Get help backing up your device in iCloud - Apple Support

I can't make a backup because there's not enough iCloud storage

A message might say you're running out of storage, but your device shows there's plenty. There's a difference between how much storage you have on your iOS device and how much you have in iCloud.

If you need more iCloud storage to back up, a message will say that you can't back up because there's not enough iCloud storage available.

Here are some tips if you're low on iCloud storage:

• Upgrade your iCloud storage plan.
• Make a smaller backup. You can back up fewer apps or delete unwanted photos and videos.
• Delete older backups that you don't need.

Ciao.