About 20.2 hours for a whole house at average use, and 10 years of warranted life on every battery we list. Runtime is the usable capacity divided by the load: 10 hours at 1 kW, 5 hours at 2 kW. Life is set by the warranty term and the minimum capacity it guarantees at the end of it.
Hours: how long it runs your house
The two regulators that set default electricity prices price a typical household at 3,900 to 4,900 kWh a year in 2026-27 (AER Default Market Offer and ESC Victorian Default Offer, checked 10 October 2026). The average of those, 4,333 kWh, is about 11.9 kWh a day or 0.5 kW around the clock. At that load a full 10 kWh battery runs the whole house for about 20.2 hours (17.9 to 22.5 hours across the regulators' usage figures), and a 13.5 kWh battery for about 27.2 hours.
| Steady load | What that looks like | 10 kWh battery lasts |
|---|---|---|
| 0.3 kW | Fridge, lights, internet | 33.3 hours |
| 0.5 kW | About an average home, averaged over a day | 20 hours |
| 1 kW | Evening peak in a small home | 10 hours |
| 2 kW | Cooking plus lights and TV | 5 hours |
| 3 kW | Air-conditioning or an oven running | 3.3 hours |
Usable capacity divided by load. Real runtimes are a little shorter because of inverter losses, and a battery can only deliver up to its rated continuous output at once, which is on its datasheet.
Most installs back up selected circuits (fridge, lighting, internet, some power points) rather than the whole house, so real blackout runtime is usually longer than the whole-house figure, not shorter.
Years: what the warranty promises
A 10 kWh usable battery costs $10,480-$13,376 installed before the federal rebate (about $9,232 after the $2,696 Cheaper Home Batteries discount at this capacity; prices as of 10 October 2026). Warranties end at the stated years or, where there is one, the stated cycle or throughput limit, whichever comes first, and most guarantee a minimum remaining capacity rather than a hard cut-off:
- Tesla Powerwall 3 (Tesla): 10 years, unlimited cycles for solar self-consumption and backup, 70% capacity at 10 years
- Sungrow SBR HV (Sungrow): 10 years, unlimited cycles for self-consumption and backup, 70% capacity at 10 years
- sonnenBatterie Evo (sonnen): 10 years or 10,000 cycles, 80% capacity
- Tesla Powerwall: 10 years, with 70% of the 13.5 kWh capacity retained at 10 years and unlimited cycles for solar self-consumption, time-based control and backup (37.8 MWh of throughput for any other use) (Tesla Powerwall Warranty (Australia and New Zealand), effective 6 May 2026, checked 10 October 2026)
Compare every battery's price, warranty and backup type on solar battery prices, and whether one pays for itself in is a solar battery worth it.
Common questions
How long will a 10kWh battery last in a blackout?
About 20.2 hours running the whole house, at the 11.9 kWh a day the AER and ESC default offers price a typical household at for 2026-27 (about 0.5 kW averaged across 24 hours). If only essential circuits are backed up, it lasts considerably longer.
How many years or cycles does a home battery last?
The batteries we list are warranted for 10 years. Cycle limits differ by brand and some warranties have none: Tesla Powerwall 3, 10 years, unlimited cycles for solar self-consumption and backup, 70% capacity at 10 years; Sungrow SBR HV, 10 years, unlimited cycles for self-consumption and backup, 70% capacity at 10 years; sonnenBatterie Evo, 10 years or 10,000 cycles, 80% capacity; Tesla's Australian Powerwall warranty sets no cycle limit for solar self-consumption, time-based control or backup, with 70% of capacity guaranteed at 10 years. The warranty ends at whichever limit is reached first.
Does a battery's capacity fade over time?
Yes, gradually. Warranties guarantee a minimum share of the original usable capacity at the end of the term, commonly 70%, rather than promising no fade at all.
Is a 10 kWh battery enough to run a house?
For one evening and night at average use, about 20.2 hours, yes. It won't run high loads like ducted air-conditioning for long, and in a multi-day blackout it needs solar to recharge during the day.