What actually needs to stay on during an outage

Ask most people what needs backup power and the first answer is "everything." It's an understandable instinct, but it's also how backup systems end up bigger — and more expensive — than they need to be. The more useful question is what actually has to stay on, and what can reasonably wait until the power's back.

The non-negotiables

• Your fridge and freezer — food spoils fast, and a chest freezer that keeps losing power and restarting doesn't last as long as one that doesn't.
• Wi-Fi and a way to charge a phone — for working from home, staying reachable, and anything that depends on a connection.
• Lights in the rooms you're actually using.
• Your gate motor, alarm and security system — a gate or alarm with no power is its own problem, not just an inconvenience.
• Anything medical — oxygen concentrators, nebulisers, chargers for mobility equipment.

What usually gets left off

Geysers, stoves, ducted or multiple air-conditioning units, pool pumps and tumble dryers all draw a lot of power relative to how urgent they actually are during a few hours without grid electricity. Most households can wait these out rather than pay to keep them running on battery.

This list is exactly what should shape how big a battery and inverter you actually need. It's also why a proper assessment starts with a conversation about what you use and when, not a generic package size picked off a price list.