You can mange your stock batch wise using different option like Model No., Size, Mfg. Date, Exp. Date
To enable this options follow the steps below

Step 1 : Click on Settings option

Step 2 : Click on Product & Stock Options

Step 3 : Under the Batch Settings, you will have the option to enable different options (3 Options are Text field & 2 are date field)
You can enable that options as per your business need.
You can also edit field names as per your need.

Now when you add new new product with Batch wise stock you will see enable fields to manage stock.