Explore our Brand-new Resource Hub & Learn the Basics of Solar & Electrical
Explore our Brand-new Resource Hub & Learn the Basics of Solar & Electrical
Posted 30 Jul
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For households that installed Tesla Powerwall 2, there hasn't been any options to expand since its CEC-approval expiry on August 23, 2025. Since, Tesla released Powerwall 3 which left some Powerwall 2 owners unsure on their next steps in upgrading energy storage.. until now.
On the 28th July 2026, Tesla announced their backwards compatibility for Powerwall 2 owners to expand their energy storage with Powerwall 3 via a software update and no hardware changes required.
Quick answer: Tesla is releasing a software update that allows Powerwall 2 and Powerwall 3 to operate together as a single combined home energy system. Your existing Powerwall 2 stays exactly as it is. A Powerwall 3 (or Powerwall 3 Expansion units) can be added alongside it. The two systems then work together, managed through the Tesla app as one unified battery. Your Powerwall 2 warranty is not affected.
Tesla has confirmed the following supported configurations at launch:
Essentially, any existing Powerwall 2 owner - whether they have one unit or up to four, can add one Powerwall 3 and up to three Powerwall 3 Expansion units. A single Powerwall 2 paired with a Powerwall 3 and two Expansion units gives you 54kWh of combined storage. At the maximum configuration, four Powerwall 2 units alongside a Powerwall 3 and three Expansion units reaches approximately 108kWh. Most households will be looking at something much more modest, typically one Powerwall 3 added to a single existing Powerwall 2.
Image: 3x Powerwall 3s connected to Powerwall 2 installation completed by Elite Power Group.
| Existing system | What you can add | Combined useable capacity |
|---|---|---|
| 1x Powerwall 2 (13.5kWh) | 1x Powerwall 3 (13.5kWh) | ~27kWh |
| 1x Powerwall 2 (13.5kWh) | 1x Powerwall 3 + 1x Expansion | ~40.5kWh |
| 2x Powerwall 2 (27kWh) | 1x Powerwall 3 (13.5kWh) | ~40.5kWh |
| 4x Powerwall 2 (54kWh) | 1x Powerwall 3 + 3x Expansion | ~94.5kWh |
From the installer's side, there are a few specifics worth understanding before booking anything in.
1. If your home is three-phase, you will only be able to get 5kW of power output in a mixed Powerwall 2 and Powerwall 3 system. For context, Tesla Powerwall 3 can deliver up to 11.5kW of continuous power output on its own. If your priority is backing up all three-phases, please talk to your installer.
2. Both Gateway 1 and Neurio Meter are not supported. If your existing Powerwall 2 system consists of either a Gateway 1 or Neurio Meter, it will need to be assessed and potentially upgraded before a Powerwall 3 system can be configured before proceeding.
3. Installations must be completed by a Tesla Certified Installer to ensure backwards compatibility configuration is compliant and correctly integrated.
It's important to note that this is not a DIY software update. The physical installation of Tesla Powerwall 3 must be done so by a licenced, Tesla-accredited installer.
Tesla have confirmed that existing Powerwall 2's will retain their original warranty and will be unaffected with the addition of Powerwall 3. However, new Powerwall 3 units will come with their own separate 10-year warranty.
Whilst Tesla Powerwall 2 is no longer CEC-approved, only Powerwall 3 CEC-approval is required when adding Powerwall 3. Your existing Powerwall 2 installation remains compliant, which means there will be no need to re-register your reapply for approval on the original unit/s.
For most existing Powerwall 2 owners, there's an opportunity to expand your energy storage and take advantage of the federal battery subsidy.
Depending on your consumption habits, Powerwall 2 with 13.5kW of capacity may be enough. However, if your usage is exceeding your solar and Powerwall capacity, definitely consider expanding your solar and energy storage.
With a national average battery size between 20-30kWh, households all over Australia are investing in higher energy capacities to maximise self-sufficiency. This means that existing Tesla Powerwall 2 can now join the rest of Australia and expand their overall energy storage capacity.
In situations where you're looking to replace your entire solar system, some may opt for a Tesla Powerwall 3-only system to take advantage of its built-in solar inverter and DC-coupling abilities.
Powerwall 3's advantage is that it can also bring higher power output of up to 11.5kW, which matters when you're running heavy loads during grid outages.
Determining if adding Powerwall 3 to your Powerwall 2 comes down to your energy consumption, budget, and goals.
Image: Tesla Powerwall 3 and expansion packs installed to a Tesla Powerwall 2
Overall, if you own Tesla Powerwall 2, now is the time to consider expanding your energy storage capacity. For newer homes, the new Powerwall 2 compatibility with Powerwall 3 won't be relevant to you as Powerwall 3 is designed to be an all-in-one solution for homes.
Want to know the differences between Powerwall 2 and Powerwall 3 - here's our full article.
Already have a Powerwall 2? You can now add a Powerwall 3 alongside it. Supported configurations, limitations and how the rebates stack in 2026.
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