Battery capacity required for home and property solar is typically that enough for three days without solar or other input. It can be far less if batteries are generator-charged.
Solar capacity is now cheap. Battery capacity, however, is increasingly costly. Quality solar modules produce usable energy even when it is partly overcast. Because of this install as much solar as you can. This ensures batteries fully charge most of the time.
Never do the opposite. Adding more battery capacity is like having multiple bank accounts to hold the same money.
This battery bank (at the author’s previously-owned property (near Broome) has 16 by 230 amp hour 12 volt gel cell batteries. Pic: solarbooks.com
Battery capacity required for home and property solar
Ideally, the battery bank should still be at 85% charge around dawn on most days. It should reach 100% by midday. If not, add solar until it is. A 45 kW/h battery bank needs a 3-5 kW hour solar array. More, however, is always best.
The type of batteries depends partially on the space available. If at a premium, consider LiFePo4. If not an AGM battery bank is initially far cheaper. It is also possible to buy secondhand AGM battery banks originally installed in standby applications and often never used.
Solar modules can be tilted to provide optimal input year-round, or optimised for either winter or summer. See: https://solarbooks.com/how-much-solar-energy-available/