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You can now ask us to assess a Powerwall 3 addition to an eligible Powerwall 2 system. Your working battery may be able to stay, but a software update alone does not establish that the whole installation is ready.
The supported combination.
Tesla’s Australian compatibility guidance specifies software version 26.26 or later, with up to four Powerwall 2 units, one Powerwall 3 and three Powerwall 3 Expansion units. Gateway 1 and Neurio Meter are not supported.
Expansion units add storage to Powerwall 3; they do not connect directly to Powerwall 2 or add another inverter’s output. We check the exact equipment, metering and installation space before recommending a combination.
The connection needs its own check.
For this mixed Powerwall 2 and Powerwall 3 arrangement on a three-phase grid connection, Tesla limits Powerwall 3 output to 5 kW. That is a condition of the combined arrangement, not a blanket limit for every WA battery or a limit on Powerwall 2 invented by the upgrade.
Western Power’s connection requirements depend on supply type and the whole installation. We include existing solar and battery inverters, export conditions and the proposed backup circuits in the assessment. A single aggregate figure cannot establish approval for every property. Read the current connection requirements.
Your existing equipment and warranty.
Tesla says an expired Powerwall 2 CEC listing does not itself require replacement when adding eligible Powerwall 3 equipment. That does not replace a condition, safety or compliance assessment of your actual installation.
Your Powerwall 2 keeps its original warranty. Adding new equipment does not restart that period. The new equipment carries its own applicable Australian warranty terms.
Check rebate history before pricing.
The Clean Energy Regulator’s battery rules limit STC support to one eligible battery system per premises; additional batteries are not eligible after the first claim. Tell us about any previous battery incentive, and have eligibility confirmed for the proposed work. The WA scheme and manufacturer offers have separate conditions.
Our current configurator separates system and Expansion choices and asks about federal rebate history where it affects the guide. Unknown or unsupported combinations stay on enquiry. Read the WA battery rebate guide before counting a deduction.
Bring the details you already have.
Send your gateway model, existing battery and inverter details, and a recent bill to PSW Life Support. We can use the Tesla app’s energy history to discuss whether more storage would be useful. Regularly having spare charge by morning is a reason to review the size carefully, rather than automatically add capacity.
Reviewed 21 October 2026. Primary sources: Tesla’s Australian compatibility and warranty documents, Western Power connection requirements and the Clean Energy Regulator, linked above.