Battery-ready and hybrid are not two grades of the same decision you can postpone. They are three separate things settled on the day the inverter goes up: whether that inverter has a battery DC input at all, whether the distribution board was opened and split into backed-up and non-backed-up circuits, and whether there is a ventilated, reachable place for a battery to live. Only the first of those appears on the quotation as a line item. The other two are physical work — done during the first installation, or paid for again later.
The twenty minutes I keep coming back to aren't the commissioning. They're the ones before, when the installer is still deciding where on the wall the inverter bracket goes.
Walk into that garage with me. The DB cover is off and leaning against the wall, screws dropped into a margarine tub on the floor because the lid went missing years ago. There's a coil of conduit near the door. The bracket is being held up against the brick, moved left, moved right, a spirit level on top, and a pencil mark that keeps getting rubbed out and redrawn. You're standing there with your coffee thinking about load shedding. The installer is thinking about something else entirely: where the conduit can get from here to there without cutting through a doorway or a cupboard carcass.
That pencil mark is essentially the whole decision. Shift it 300mm and you change what the house can do in four years' time.
Three things get decided before lunch, and only one of them is on the invoice
The invoice will say panels, inverter, mounting, installation, CoC. What it won't spell out is what the installer chose while you were making coffee.
The DC input on the inverter
Some grid-tied inverters have no battery DC terminals at all. Their DC side is the PV input and nothing else. On those, there is no later upgrade — the inverter gets replaced or the storage idea dies. Battery-ready means the opposite: a battery DC input exists, plus a defined backup output, with no battery fitted on the day.
But "there is an input" is not the same as "anything will work on it." The manufacturer defines which chemistries and which voltage window that input accepts, and that list lives in the manual for that specific model. It does not live in the installer's head. I've seen competent, careful installers be confidently wrong about a model they haven't wired before, because they were going on what worked on the previous job. Ask to see the page.
The split at the distribution board
A backup output is useless if every circuit in the house is still sitting on one side of the board. The backed-up circuits have to be separated from the rest: which plugs, which lights, whether the geyser or the stove is anywhere near it. That separation is work done while the board is open and the cover is off.
Do it on installation day and it's part of a job that's already happening. Do it later and the board is opened a second time, circuits are reworked, and the Certificate of Compliance you already hold describes an installation that no longer matches what's on the wall.
The wall the battery will eventually live on
This is the one people skip, and it's the one that bites. Batteries want a temperature range that isn't extreme, clearance around them, and ventilation. A west-facing garage that turns into an oven by 15:00 is not the same proposition as a shaded passage. Cable routing has to get from the battery position to the inverter without a fight.
On the first installation, none of that is a problem. The garage is empty, the walls are accessible, the installer is already on site with the tools out. Two years later the garage is full, there's a workbench against that wall, and the run you'd need involves lifting boards or chasing brick.
Why normalising quotes won't surface this
When you compare proposals on rand per kWp, you're comparing generation. The storage decisions are invisible in that number — they've been absorbed into a line called "installation" and they vary enormously between one quote and the next. Two quotes can show the same panel count, the same inverter class, and the same total, and one of them leaves you able to add a battery in a weekend while the other leaves you unable to add one at all.
The way around it is to stop reading the quote as a price and start reading it as a description of what will physically exist. Ask what the backup output will feed. Ask where the battery would go if you added one. The answer tells you more than the pricing table.
The paperwork follows the installation, not the intention
Your municipal SSEG registration and your Certificate of Compliance both describe the system as it stands on the day they're issued. NRS 097-2-1 and SANS 10142-1 obligations attach to what's actually installed. Adding storage later is a change to that installation, and the registration and the CoC have to be updated to match.
That's not a reason to avoid storage. It's a reason to know, before you sign, that the second phase is a paperwork event as well as a hardware event, and to be sure the first phase was documented in a way that makes the second phase straightforward.
What I'd want answered across the table
Does this inverter have a battery DC input, and can I see where the manufacturer says so? Which chemistries and what voltage range does that input accept? Will the board be split on installation day, and which circuits land on the backed-up side? Where does a battery go, what clearance does it need, and how does the cable get there? Is the SSEG application being handled now, and what does adding storage later do to it?
None of those are technical questions. They're questions about what gets built while the drill is out.
A last thing about the word "hybrid"
The label on the box is not the point. Some equipment sold as hybrid is genuinely ready for what comes next; some is hybrid in the sense that it can manage a generator input. What matters is what's physically present: a DC input that will accept a battery within a stated range, a backup output that has somewhere to go, and a space that a battery can occupy without cooking or crowding.
Get those three settled in the half hour before the bracket goes up, and the battery upgrade becomes a purchase. Miss them, and it becomes a renovation.
