Guides / Home batteries · Updated
Tesla Powerwall 3: how long will it run my house?
From the maker's own datasheet, read November 2026. Backup times divide usable energy by your average load.
Short answer
The Tesla Powerwall 3 stores 13.5 kWh you can use and supplies 11.5 kW continuously, starting motors up to 185 A locked-rotor current. At a 1 kW average load one unit lasts about 13 h 30 min; at 3 kW, about 4 h 30 min.
Backup time at an average load
| Average load | One unit | Two units |
|---|---|---|
| 0.5 kW | 27 h 0 min | 2.3 days |
| 1 kW | 13 h 30 min | 27 h 0 min |
| 1.5 kW | 9 h 0 min | 18 h 0 min |
| 2 kW | 6 h 45 min | 13 h 30 min |
| 3 kW | 4 h 30 min | 9 h 0 min |
| 5 kW | 2 h 42 min | 5 h 24 min |
| Fridge only (64 W average) | 8.8 days | 17.6 days |
hours = 13.5 kWh ÷ average kW
Your average load is your daily kWh ÷ 24; the home battery backup calculator works it out from your bill and checks your peak load and air conditioner too.
Will it start my air conditioner?
The maker rates it to start motors drawing up to 185 A locked-rotor current (LRA). Your AC's LRA is on the outdoor unit's nameplate; if it's higher, the battery may not start it; ask the installer what they recommend.
Specs
| Usable energy | 13.5 kWh |
|---|---|
| Continuous power | 11.5 kW |
| Motor start | 185 A LRA |
| Efficiency | 89% solar to battery to home; 97.5% solar to home |
| Warranty | 10 years |
| Charging | 5 kW AC |
Other home batteries
- Enphase IQ Battery 5P: 5 kWh, 3.84 kW
- FranklinWH aPower 2: 15 kWh, 10 kW
- SolarEdge Home Battery 400V: 9.7 kWh, 5 kW