What size system does your load actually need?
List what you want backed up. You get an inverter range, the bus voltage to build at, and the battery bank sized three ways — lithium, tubular and AGM — with every assumption behind it printed underneath.
It is the same arithmetic I run before quoting my own installations. The systems it was calibrated against are photographed on the solar page.
Your load list
The watts are typical figures for that kind of appliance, not a measurement of yours. Change any of them to the number printed on your own unit — that is what makes the answer worth having.
| Appliance | Qty | Watts | Hrs/day | When | Back up | Remove |
|---|
Swipe the table sideways for hours, when, and back up.
Untick Back up to leave something on mains only. It stays on the list and is named in the result, so nobody is surprised later by a cooker that was never in the number.
What this is not
It is not a quote and it is not an engineered design. It has not seen your roof, your shading, your cable runs or your existing board, and it prices nothing.
What it is good for is the conversation before any of that: it tells you which bus voltage to build at, roughly what the bank has to hold, and which chemistry the numbers actually favour.
Talk it throughWhat the answer above assumes
Every one of these moves the result. If you disagree with one, you know exactly which number to argue about — which is the point of printing them.