If you have access to the electricity grid, you don't need batteries to power your appliances at night.
Whatever is running during the day, while the sun is out, will typically run off the power generated by the solar panels. When that power is reduced, such as in the early morning, or late afternoon onwards, the inverter in your solar installation will automatically draw power from the electricity grid.
Installing batteries and running them at night is possible, but is often more expensive than powering your appliances from the electricity grid. For that reason, we don't suggest it.