Solar batteries: usable capacity, power and compatibility
Sources checked
Compare usable capacity in kWh: the energy you can actually withdraw at the supplied settings. The label often gives nominal capacity instead. Power in kW describes how quickly the battery and inverter can supply appliances; it is a different requirement.
Choose capacity and power separately
Start with consumption after solar production ends and the surplus available to recharge the battery. Ask for usable capacity, continuous charge/discharge power, reserve settings and any phase limits. A package labelled 10 kW may describe the inverter rather than the battery's size.
In the website's reference scenarios, storage helps evening-heavy households more than households already using much of their electricity during the day. Larger storage does not necessarily produce a proportionately larger benefit.
Confirm the complete supported combination
The exact battery model must be supported by the exact inverter, including the required control equipment, communication and firmware. Sharing a brand name does not establish compatibility. Check location requirements, warranty conditions and who handles future service.
Backup needs supported equipment, connected backup circuits and an energy reserve. It is not an automatic consequence of having a battery. Compare complete installation prices and the additional benefit of storage before deciding.