Tesla powerwall 2 cells

I'm currently debating what to do with a powerwall 2 I brought. Does any1 know if can be used as a battery just as is without being hooked to a gateway as I don't have that part? My house currently runs off lead acid batteries but would be good to use as is and not sacrifice to get cells from. I also not want to spend another 2k+ to get gateway.
Has any1 had any experience with genuine tesla powerwall?
There is a family substantial inverter ontop of battery would any1 be interested in making offer on it?