1500W? At 12V that's 125A - That is fucking dangerous! Most sockets are rated at 20A. Most inverters that are >300W use crocodile clips, or preferably screw-down terminal rings. The cable looks way too thin too. That's a fire waiting to happen....
In the US you would need #2 [AWG] gauge wire to handle 125amps safely, and that's just handling the current, nothing to do with proper grounding or anything.
Also just for reference, many older homes in the US would only have 100 amp service from the pole, meaning this thing is pushing more amps than a whole house potentially.
