u/Final-Peak7334

I have a solar as per below

Panels: 16 × 440W ≈ 7.0 kWp system
Inverter: FoxESS HYD 5 kW
Battery: Fox ESS EP11 ≈ 10.4 kWh usable

Inverter and battery are in the garage … I’m looking at expanding capacity by adding panels to the garage roof and/or possibly adding another battery

Would I need a different/additional inverter?
Could the battery be installed by me (eh are they plug and play) or do I need specialist solar installer or sparky to do this
Is it cheaper to buy stuff myself and get someone to fit or get someone to supply & fit