Define what you want the battery to do
Is the goal to move solar into the evening, use a particular tariff window, provide selected backup, or prepare for an EV? The answer shapes the architecture and whether a retrofit is sensible.
Identify the existing equipment
Take clear photos of the inverter and battery labels without sharing meter identifiers. Note the approximate installation date and whether monitoring still works. Existing system details influence which retrofit paths can be considered.
Check solar production and household use
A recent bill and monitoring data, where available, help show how much solar is exported and when grid energy is used. A battery discussion needs both sides of that picture.
Bring the switchboard and phase into view
Available board space, supply phase, export controls, cable routes and equipment location may matter as much as the battery brand. A site visit makes these constraints visible.
Be specific about backup
Selected backup circuits need to be agreed and designed. Available battery charge, circuit loads and wiring affect what can operate during an outage; it should not be assumed that every circuit will be included.
Useful first pack: a recent bill, inverter label photo, battery label photo if present, monitoring screenshot, and a short note describing the outcome you want.
Ask whether keeping, adapting or replacing is cleaner
Sometimes the existing solar can remain largely as it is. Sometimes a different architecture or staged replacement is clearer. A useful assessment explains the trade-offs and avoids replacing serviceable equipment without a reason.