Powerwall 3 Expansion Pack
Store more energy with your existing Powerwall 3. Each Expansion adds 13.5 kWh of usable storage, using the inverter you already have. Add up to three for a total capacity of 54 kWh.
Premium Tesla Powerwall Certified Installer since 2021
More storage for the system you already own
More capacity, same inverter
An Expansion adds battery storage using your Powerwall 3’s existing inverter. You manage everything through the same Tesla app.
Backed for ten years
Each Expansion comes with its own ten year Tesla warranty, covering at least 70% capacity retention at the end of the warranty period.
Double your storage with one Expansion
Add 13.5 kWh to your Powerwall 3 for 27 kWh of total storage. Keep more of your daytime solar to power your home after dark.More storage, managed in one app
Your Powerwall 3 and Expansions work together as one system in the Tesla app. Check your combined charge level and see how energy flows through your home.
Your home energy, at a glance.
Your day, hour by hour since first light, and where the energy went.
When the grid goes down, your lights stay on.
Is an Expansion right for your home?
Extra storage could help if you regularly export excess solar, run out of battery power overnight or want backup to last longer. We review your energy use and check your Powerwall 3’s compatibility before recommending an Expansion.
Adding an electric car or a heat pump
Your energy needs can grow as you switch more appliances to electricity. We help you work out whether extra storage would be useful, based on how much energy you use and when you use it.
Adding storage to your Powerwall 2
Expansions connect to Powerwall 3. If you have a Powerwall 2, talk to an Energy Geek about your options for adding storage. We’ll check your existing system and explain what’s possible.
Solar battery rebate
See how the Cheaper Home Batteries discount applies when adding one, two or three Expansions to your Powerwall 3. Any eligible discount comes off your purchase price, so there is no separate claim afterwards. The discount per kWh reduces as storage capacity increases, and capacity above 50 kWh does not attract a discount.
| Units | Usable storage | Federal discount | Added by this step |
|---|---|---|---|
 | 13.5 kWh | $3,276 | Full rate |
| 27 kWh | $5,328 | +$2,052 |
| 40.5 kWh | $5,940 | +$612 |
| 54 kWh | $6,264 | +$324 |
Rates as at 29 July 2026 · Clean Energy Regulator · installs to 31 December 2026
Powerwall 3 and Expansion specifications
Each Expansion adds 13.5 kWh of usable storage, sharing your Powerwall 3’s inverter and solar connection. Add up to three Expansions for 54 kWh of total capacity. Extra storage lets you run your home for longer without increasing the system’s power output.
The Expansion has an IP67 rating, operates from −20°C to 50°C and measures 1105 × 609 × 168 mm at 110 kg. It comes with a ten year Tesla warranty, with unlimited cycles for eligible uses. All storage figures shown are usable capacity.
| Property | Tesla Powerwall 3 | Powerwall 3 Expansion |
|---|---|---|
| Usable capacity | 13.5 kWh | 13.5 kWh |
| Continuous power | 5, 10, 11 kW | None of its own. The Powerwall 3 supplies it |
| Solar input | 20 kW DC, straight into the unit | None. Solar wires into the Powerwall 3 |
| Backup transition | Not stated | The Powerwall 3 handles it |
| Expandable to | Up to 4 units: 54 kWh, plus expansions | Three per Powerwall 3, 54 kWh |
| IP rating | IP67 | IP67 |
| Operating range | −20°C to 50°C | −20°C to 50°C |
| Dimensions | 1105 × 609 × 193 mm | 1105 × 609 × 168 mm |
| Weight | 130 kg | 110 kg |
| Warranty | 10 years, unlimited cycles | 10 years, unlimited cycles |
| Solar inverter | Integrated, 3 MPPTs | None. The Powerwall 3 has it |
| Backup | Single phase: whole home Three phase: partial home | Lengthens the Powerwall 3's backup |
| Monitoring | Tesla app | Tesla app, through the Powerwall 3 |
| Powerwall 2 compatibility | Yes | Powerwall 3 only |
- Tesla Powerwall 3. Tesla Powerwall 3 specification, as published on Sunstak's product page, read 29 July 2026
- Tesla Powerwall 3. Tesla Powerwall 3 datasheet, read 14 August 2026
- Powerwall 3 Expansion. Tesla Powerwall 3 datasheet (Australia), 19 August 2025 revision, read 21 August 2026
- Powerwall 3 Expansion. Tesla Powerwall Warranty (Australia and New Zealand) Rev 1.16, read 21 August 2026
Every installation backed by the Sunstak guarantee
Sunstak master installers
Our master installers have completed at least 100 installations with 5/5 star reviews.
Installation with no surprises
We confirm the scope, price and installation plan. You'll know exactly what's included, what happens next and what to expect on the day, with no last-minute variations or surprises.
Roof leak guarantee
If your roof leaks after our installation, we pay you $500 cash and fix it immediately.
Stock guarantee
If we can't supply the product on your design, we replace it with an upgrade and your price does not move.
Expand with Sunstak
Speak with one of our Energy Geeks today.
- Solar Accreditation Australia approved
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Having used two other installers previously, the Sunstak experience is head and shoulders superior…
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