BMS for packs

Can you use a BMS on a pack rather than cells.
My packs are 7.4v li po. The BMS that I have read about only go as high as 4.2v

Depends on the bms. Most bms require the cell 1 slot to be 4.2V max, or 3.7 if LiFePO4. If it's higher than that, it'll trigger the over voltage protection.

However, if a bms could work at that level, the further away from the cell level you go, the worse imbalance could occur. Just because the "pack" is the proper voltage doesn't mean the "cells" are proper voltage.

7.4, sure. But 1 cell could be 2.4 and the other 5V.

Thanks Korisham, understand know

You need the bms to be per parallel pack
You cannot skip this. 7.4v would be a 2s