Is it possible to connect a pylontech to this 5year old 6kw ellies inverter 

Thank you Keith 

15 minutes ago, calypso said:

but I would go out on a limb to say no. 

+1

If you can set the charge profile (Voltages) then it would be possible. But I doubt this inverter has that. 
The options on the battery list (left side of the image) don't include Lithium and also don't match what LiFePO4 can handle.

I don't think that would work, no. 

I have set up this inverter as gel European battery with a dyness 3.5kw lifepo4 and ran for a year . No problems as the BMS took care of the charge and discharge .