Renaming devices

Is there a way to change the name of a device. Ie from SmartSolar MPPT 100/30 XYZ etc to (say) LARGE ARRAY.?

Yes, via victron connect or the GX device entry.

In Victron connect, Tap the gear wheel in the top right corner, then the three dots in the top corner and select ‘product info’

You can edit the name from there;

Edit: Dirk has explained it better than me in this topic;