Odd inefficiencies in Growatt 12000T DVM unit vs Batrium

[tweekzilla]

Charging question using a GROWATT 12000T DVM and Batrium.

I've been upping my charge current from the grid each night on a new system. I started off at 30A and moved upto 60A (into a 280aH LiFePo). I noticed that power usage by the inverter changed each night from 2.8kW at 40A, 3.6kW at 50A and 4.3kW at 60A. I presume I'm CC but charging at 55V setting the power loads should really only be 2.2kW, 2.7kw and 3.3kW. The interesting thing is Batrium shunt only shows power at 2.5kW, 2.5kW, 2.7kW. So something here doesn't make sense. I've also confirmed that the growatt is pulling more power per Amp setting - It's just not getting to the battery? Table below for easy reading (Note grid contains other loads so look at change)

Setting	Batrium shunt	Inverter	Grid	Expected
40A	2.5kW	2.8kW	4.3kW	2.2kW
50A	2.5kW	3.6kW	4.6kW	2.8kW
60A	2.7kW	4.3kW	4.9kW	3.3kW

Note the charger was set to utility only during charging (no loads from battery) and the SoC was probably about 75% upto around 90% by the end.

Thoughts as it just looks the inverter is dumping the excess power as heat but there's no fancy connection to the BMS so why would it do that? Bartium shunt current below showing virtually no change from 40A to 60A max charge current

 

[MichaelRayHam]

What protocol did you use to get the Batrium to talk to the Growatt?