How long will my battery last?

Pick a battery size and the loads you'd want to keep running, and we'll work out roughly how many hours of backup you'd get.

Battery size

Assumes 90% usable capacity — LiFePO4 batteries are never run all the way down to empty.

Loads to keep on backup

LED lights, whole house 80 W
Fridge + freezer 150 W
TV + decoder 120 W
Wi-Fi router + fibre 25 W
Laptops & phone charging 80 W
Alarm, gate & cameras 60 W
Microwave 1200 W
Desktop computer 200 W

≈ 0 hours

Total draw: 0 W · 4.5 kWh usable

Sunshine extends this. This estimate is for the dark — during the day the panels carry these loads directly and the battery barely discharges, so backup time really matters overnight or on a heavily overcast day.

Why kettles, geysers and heaters stay off backup. These typically draw 2–3 kW each — enough on their own to overload a backup circuit sized for essentials. See how the inverter splits your circuits. That said, today's larger inverters and battery banks can comfortably carry more of these — if you'd like them to keep running during a power outage, we can size your inverter and battery bank for it.

Estimate only — actual backup time depends on your specific system, battery health and how your household really uses power.