Chinese inverter discharges batteries without anything connected

[TomC4306]

Nope on SUB mode inverter use 100W from grid its not good.
On SBU mode inverter is working on battery but cutoff low dc should charge inverter as well from grid, right now inverter use all power from battery until battery are flat.
Its a firmware bug or what?

No, you don't have the settings set correctly.
User error.

 

[john1819]

No, you don't have the settings set correctly.
User error.

There is another thing what i found.
On APL take no idle power from grid only from battery on UPS take 200W from grid, at night, charging battery from grid is off