A battery controller has to measure and coordinate the site correctly. CT placement, smart-meter configuration, controlled-load circuits and export controls can change what the battery sees and what it can do. These are verification points—not DIY wiring instructions.
OEM systems commonly rely on site metering or current transformers at a defined measurement point. Fronius recommends its Smart Meter at the feed-in point and supports additional meters for individual consumers or generators. Enphase documents specific failure states when consumption CTs are configured for the wrong topology, omitted while enabled, or installed with reversed polarity.
Fronius GEN24 metering guidance → · Enphase CT verification brief →
Australian Government guidance describes controlled loads as specific appliances connected to a separate meter circuit. Depending on the metering/control architecture, a battery system may not measure or supply that circuit in the same way as general household loads. Hot water is the common example; pool pumps and EV charging can also use controlled-load arrangements.
Australian Government tariff guidance →
Network connection and export limits are separate constraints. Australian Government guidance notes that export limits may apply by phase and that export-limiting equipment/configuration may be required. GoodWe's Australian hybrid-inverter documentation explicitly uses Smart Meter/CT measurement in its export-power-limit function.
Australian Government network/export limits → · GoodWe Australia export-limit controls →
Do not assume that AC coupling means existing solar automatically keeps running during an outage. OEM architectures can impose controller, CT, firmware, power-ratio and frequency-control conditions. Sungrow's current Australian Energy Bridge application note, for example, documents additional CT and power-control requirements for third-party PV retrofit operation during backup. Fronius separately notes that additional AC sources may charge the battery in normal grid-tied operation while not being permitted to feed the emergency-power circuit in some GEN24 backup configurations.
Sungrow Australia retrofit application note → · Fronius GEN24 backup guidance →
CT orientation, meter wiring, protection, network settings, switchboard changes, backup circuits and commissioning are electrical-design/installation work. The point of this page is to expose the questions before a design is accepted.
A separate circuit does not prove a battery cannot interact with that appliance. It means the actual metering and supply arrangement must be established rather than inferred from the electricity bill or inverter model.
If a large load sits outside the consumption data you entered, the sizing result can understate your real after-solar demand.