I'm still interested in the piece of kit we are talking about here, people have many different ideas of what a battery management system is, we could be talking:-
inverter, charger, combi , alternator controller, battery monitor etc etc
If as I suspect it is, an alternator controller then I doubt it is needed at all on a modern Canaline engine, no benefit what so ever.
So I would recommend to the OP just to bin it rather than being offered 30% discount again on a piece of kit you really don't need.
( Qualifier.... unless of course you have retained some sort of diode split charging system at re-engine time) Then you don't need that either!
A