Implementing batch-code in an existing system

Hello

We’ve been using ERPNext for our factory for 5-6 years - using mainly inventory, buying and manufacturing tools. Till date, we have never used batch-code feature - so all items are marked 0 on “Has batch no”. Now we are looking to integrate batch numbers with ERPNext but the system is not allowing changing that field for any item which has even a single stock entry.

Please guide me how to proceed here as we have ~2,000 item codes with multiple BOMs, and of course historical purchase, sales, stock data - so recreating all items’ duplicates is not really a practical solution.

Regards,
Shashank

Bumping this up. Really looking for help here - I’m stuck and this is an important area from audit as well as way-of-working point of view for us.