There is the PW+ battery unit with higher output power, and there is also the solar PW2 which combines the PW+ battery unit with a separate-but-connected top solar module.
I think this may be the other way around. We have the spec-sheet for the combination Powerwall/solar-inverter and it's titled "Powerwall+".
Meanwhile we haven't seen any Tesla documentation for the separate higher output Powerwall (which Elon called "plus" on the earnings call), but some state certification documents for it call it "Powerwall 2.1"