Duracell 10kw expected output...

[Cawsie]

Hi all. Newbie here.

I have 2 x 5 kwh Duracell batteries coupled to a 6kw Solis inverter and 21 450w panels.
They all work great but there is one thing niggling me. Let's say my batteries are fully charged going into the night and my house load goes up to say 6kw. My batteries kick in but they never really get above 3.5 kw feeding my house load. The rest of the load is coming from the grid. Is this normal for my setup?
When it's daylight and there's solar, it's not a problem as the Solis won't then grid draw.
I have asked my installer but he must be away so i thought i'd ask on here.

Cheers
Steve

 

[1234enough]

Bit more info required - list of equipment / settings of equipment / connections/ schematic.
Power being supplied can be affected by many things - such as settings of system/ capability of system / temperature ect ect.