It shouldn’t take longer than about 5-20 minutes for the backup to complete though it all depends on how much data is on your device. iExplorer is making an iTunes backup at that moment. If it seems stuck on making a backup (taking longer than about 20 minutes), please close and reopen iExplorer and right-click on Backup in the left panel and choose to Back Up Now which will make a new iTunes backup. If the backup still doesn’t finish or load, please make sure you have your device setup to backup to your computer and not to iCloud. You can check these settings on the Summary tab for your device (the first screen that comes up when you click on your device in iTunes). If your device was configured to backup to iCloud, please change it to “This computer” and then try opening iExplorer and create a new backup (right-click on Backup in the left panel and choose to Back Up Now).
If you’ve done all of that, and the Backup section still won’t load or complete a backup, please try completely closing iExplorer, open iTunes and make a backup for your device manually in iTunes by clicking on iTunes File menu > Devices > Back Up. Then, once the backup is finished, reopen iExplorer and check the Backup section again.
If you receive any errors while backing up directly in iTunes, see the Apple article below for steps to resolve it:
https://support.apple.com/kb/TS2529