2026-06-25

Powerwall 2 to Powerwall 3 Upgrade in Multi-Powerwall 2 System

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Note
This installation configuration will be supported in a future Powerwall firmware version. Future service work can be planned, but this configuration cannot be installed at this time; stay tuned for updates.

Overview

  • 2026-06-23: Released new procedure.

Follow this procedure to replace a Powerwall 2 with a Powerwall 3 on an existing multi-Powerwall 2 site. One Powerwall 3 with up to three Expansion units can be installed on an existing Powerwall 2 site.

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CAUTION
This system configuration is not available for multi-Powerwall systems that are required to comply with Power Control System (PCS) standards. Even if individual Powerwalls are limited by breaker size, some sites use PCS features to manage site import and export, which impacts how the system operates.

For sites that must comply with PCS standards, replace all Powerwall 2 units with Powerwall 3 units to ensure the site remains compliant.

In this configuration, Powerwall 3 is installed and connected to Powerwall 2 via communication wiring. Important notes about this configuration include:
  • During device setup, Powerwall 3 becomes the Site Controller for the system; Backup Gateway 2 remains the islanding controller and Site meter
  • The Powerwall 3 On/Off switch controls the entire system; each Powerwall 2 switch only controls that unit
Figure 1. Maximum System Size for Mixed Powerwall 2 and Powerwall 3 System
Table 1. Existing Configuration Support
Existing Configuration Required Action Before Powerwall 3 Swap Can Proceed
Up to (4) Powerwall 2 units installed with Backup Gateway 2 N/A
More than (4) Powerwall 2 units N/A (not compatible)
Powerwall 2 installed with Backup Gateway 2 and Backup switch
Powerwall 2 installed with Backup Gateway 1 and Neurio meter

Replace Backup Gateway 1 with Backup Gateway 2
Replace Neurio meter with Tesla Remote Meter
Powerwall 2 installed with Backup Gateway 2 and Neurio meter Replace Neurio meter with Tesla Remote Meter
Powerwall+ system See Legacy Powerwall to Powerwall 3 Upgrade for instructions to replace all units with Powerwall 3

Prerequisites

  • This procedure requires Group Lockout/Tagout (LOTOV) if more than one worker is involved. Each worker must apply their own lock and tag or use a group lockbox system in accordance with site procedures. Each worker is responsible for removing their own lock and tag upon completion of work.
  • Take a photo of the signed LOTOV form used at the site when service is complete. Each worker must sign on and sign off on this form. If there is no LOTOV form at the site, in North America, use the LOTOV Form. In all other regions, follow the local LOTOV standard. For more information, refer to the Tesla Global LOTOV Standard.
  • Only trained and authorized personnel are permitted to perform this procedure.

Hazards

Figure 2. Crush Hazard
Figure 3. Shock
Figure 4. Cut Hazard

Safety and PPE

  • Closed-toe shoes with composite toe and leather upper
  • HRC2/CAT 2 coveralls or arc-rated, long-sleeved shirt (tucked in) with arc-rated pants
  • Safety glasses (ANSI Z87.1 or EN 166)
  • Class 0 insulated electrical gloves with leather protectors (ANSI A4 cut-resistant, ANSI A3 abrasion-resistant, ASTM CAT2)
  • Cut-resistant gloves (ANSI Cut Level 3 or EN 388 Level C)
  • Proving unit (Fluke PRV240 or equivalent)
  • Lockout/Tagout kit (locks, tags, hasps, lock box)

General Equipment

  • Paint pen

Required Parts and Tools

  • Powerwall dolly
  • Torx T20 screwdriver
  • Small flathead screwdriver
  • If installing a larger breaker and wiring for Powerwall 3:
    • Appropriately sized AC breaker for Powerwall 3 unless reusing Powerwall 2 breaker
    • Minimum 300 V rated, 70°C rated, copper (Cu) wire, 10 AWG to 4 AWG (6 mm² to 25 mm²), for AC wiring

Plan New System Install

  1. Before starting the service work, greet the homeowner if they are home, describe the work that will take place, and ask for any required information such as:
    • Gate/garage or home access codes that may be needed to access the Powerwall location
    • Location of the load center and Gateway
    • Wi-Fi SSID and password for connecting the new Powerwall to the internet
  2. Place cones and caution tape to establish a boundary at least 5ft around the area of work.
  3. Document the existing system configuration:
    • Record the number of Powerwall 2 units
    • Document the wiring layout and Backup Gateway 2 location
    • Take photos of the existing installation for later reference
  4. Choose the mounting location for Powerwall 3 (and Expansion unit(s) if applicable). Consider the following:
    • When connecting Powerwall 3 to the existing system via communication wiring, Powerwall 3 must be connected to the last Powerwall 2 in the daisy chain (see Connect Powerwall 3 to the Existing System via Communication Wiring for wiring diagrams).
    • The maximum communication cable length for the entire chain (from the Backup Gateway 2, through all Powerwall 2 units, to Powerwall 3) depends on the communication wire size used:
      • 150 ft (45 m) for 16 AWG (1.5 mm2) wire
      • 82 ft (25 m) for 18 AWG (0.8 mm 2) wire
    • If the system includes wall-mounted Expansion units, ensure the maximum combined harness length is not exceeded (see install manual for details).

Remove Powerwall 2

  1. Put on arc flash PPE.
  2. Perform Backup Gateway 2 Lockout/Tagout.
  3. Disconnect and remove the Powerwall 2 breaker if it is not being reused.
  4. Remove arc flash PPE and put on cut resistant gloves.
  5. Remove the Powerwall 2. Repeat if removing a second unit.
  6. Remove the screws attaching the Powerwall 2 mounting bracket to the wall, then remove the bracket. Clean the wall surface to remove any sealant or dirt.
  7. Patch any holes left from the mounting hardware using a method suitable for the wall surface.
    Informational PurposesAn informational icon, calling your attention
    Note
    The original Powerwall 2 mounting holes cannot be reused because the Powerwall 3 mounting bracket is a different size from the Powerwall 2 bracket.
  8. Remove the fittings from the conduit. Change the conduit run as needed to accommodate the new Powerwall 3 wiring.
    Informational PurposesAn informational icon, calling your attention
    Note
    In most cases, when the original conduit run is short, the existing conduit should be removed and replaced with new conduit. In cases where the conduit will be reused or extended, ensure the fittings are appropriate and all connections are compliant with local code.

Install Powerwall 3

  1. Follow the instructions in the Powerwall 3 Install Manual to wall-mount Powerwall 3 (and Expansion unit(s) if applicable).
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    Note
    It is recommended to install the new unit(s) in the same locations as the unit(s) being removed if feasible.
  2. Connect Powerwall 3 to the Expansion unit(s) as defined in the Powerwall 3 Install Manual (if applicable).
  3. If installing a new larger breaker, run appropriately sized AC wiring and connect Powerwall 3 to the breaker.
    Informational PurposesAn informational icon, calling your attention
    Note
    If it is possible to reuse the Powerwall 2 breaker, or if installing Powerwall 3 with a 30 A breaker and configuring output power / current of 5.8 kW / 24 A, the existing AC wiring and breaker from the original Powerwall 2 can be reused, so long as the wiring is at least 10 AWG (6 mm2).
  4. If the original system included a Neurio remote energy meter, remove the Neurio meter and CT(s) and replace them with Tesla Remote Energy Meter and CTs.
    1. Verify the CT orientation matches the direction of the current flow.
    2. Ensure the CT(s) are fully closed around the conductor(s) they are measuring.
    3. Ensure the CT(s) are securely connected to Tesla Remote Energy Meter.
    4. Take photos of the Tesla Remote Energy Meter and CT installation.

Connect Powerwall 3 to the Existing System via Communication Wiring

  1. Run the communication wiring between Powerwall 3 and the last Powerwall 2 in the daisy chain.
  2. Connect the communication wiring to Powerwall 3 as defined in the Powerwall 3 Install Manual.
  3. Connect the other end of the communication wiring to the top 4-pin socket (labeled “OUT”) in the Powerwall 2 wiring compartment.
  4. If the communication wiring has a drain wire:
    1. Cut back the drain wire at the Powerwall 2.
    2. Wrap the drain wire around the grounding conductor lead in the Powerwall 3.
    Figure 5. Detailed View of Communication Wiring Between Powerwall 3 and Last Powerwall 2
    Figure 6. Communication Wiring for Powerwall 3 with (4) Powerwall 2 Units
    Informational PurposesAn informational icon, calling your attention
    Note
    Powerwall 3 must be connected to the last Powerwall 2 in the daisy chain. In the event the Powerwall 2 being removed is not the last unit:
    1. Disconnect the communication wiring from the faulty Powerwall 2.
    2. Connect the remaining communication wiring from the previous Powerwall 2 "OUT" 4-pin socket to the "IN" socket on the next Powerwall 2 in the daisy chain.
    Powerwall 3 is then still connected to the last Powerwall 2 in the daisy chain as shown below.
    Figure 7. Communication Wiring for Powerwall 3 and Powerwall 2 System After Removing a Powerwall 2
  5. If the original system included a System Shutdown Switch connected to the Backup Gateway 2:
    1. Remove the Rapid Shutdown (RSD) wiring from the Backup Gateway 2 Aux connector and connect it to the Powerwall 3 RSD terminals. See the Powerwall 3 Install Manual for details.
    2. Install a wire jumper in the Backup Gateway 2 Aux connector in place of the RSD wiring. If needed, a wire jumper can be created using 18-16 AWG (0.8 - 1.5 mm2) wiring.

Power On the System and Perform Device Setup

  1. Inform all site personnel that power is being restored.
  2. Remove all LOTO locks
  3. Install any electrical panel deadfronts that were previously removed.
  4. Put on arc flash PPE.
  5. Energize Backup Gateway 2.
  6. Remove arc flash PPE.
  7. Connect to Powerwall 3 using the Tesla One app and perform device setup.
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    Note
    After turning on the unit, allow 2 - 3 minutes for the Wi-Fi signal to begin broadcasting.
  8. Navigate to the Networking tab and connect the unit to the customer's Wi-Fi, if available. Refer to Configure Internet Connection section in the Powerwall 3 Device Setup Guide for more information.
  9. On the Software tab, check for software updates and download any available updates.
    Informational PurposesAn informational icon, calling your attention
    Note
    Powerwall 3 must be updated to software version 26.18 or later to commission a system with Powerwall 2 units.
  10. Navigate to the System tab and verify that all units are present. If the communication is not established, inspect the communication wiring between the units. See Connect Powerwall 3 to the Existing System via Communication Wiring for communication wiring diagrams.
  11. Set the Powerwall's maximum power/current output using instructions in Configure Powerwall 3 Maximum Power / Current Output.

    This value must be set to comply with permit requirements. Refer to the plan set to determine the correct values.

    Warning IconA warning icon, calling your attention to a possibly risky situation
    Warning
    This step is critical. Failure to complete it can result in electrical faults in the wiring due to overcurrent. Do NOT start the system before setting this limit.
  12. Use a paint pen to mark the configured power output limit on the product label on the left side of the Powerwall 3 unit. Mark the box corresponding to the limit set.
  13. Navigate to the Metering tab to configure the Tesla Remote Meter and CTs if installed.
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    Note
    If Meter Y is used in the Gateway, it does not need to be replaced. Only Neurio meters and CTs must be replaced.
  14. Navigate to the Settings tab to set the grid code and solar installation type. If the site requires additional settings, set those under the Advanced Settings option.

    Refer to Configure Settings for more information.

  15. Perform a Backup Test to confirm the system disconnects from and reconnects to the grid as expected. If the Backup Test is not successful, inspect the system wiring. Escalate to Support if needed.
  16. Perform an E-Stop Test to confirm the System Shutdown Switch is functioning as expected.
  17. Complete the Installer Registration as follows:
    1. Select Registration > Installer Info.
    2. In the Company Name field, verify that the name of the company performing the installation has automatically been filled in. If the company name is not present or is not correct, search for your company to select it.
      Informational PurposesAn informational icon, calling your attention
      Note
      The Company Name is the field that links a partner to a site, meaning this is the field that allows a company to view the site in Powerhub.
    3. In the Email field, leave the email address of the installer completing the installation. This email address is used to track Tesla Academy training completion and the Pro Score inside Tesla One.
    4. If there are additional Partners that should have access to the site in Powerhub, add them as follows:
      1. Select Add Partner and search for the partner name to select it.
      2. Repeat this step if needed (up to two partner companies can be added).
  18. Complete the Customer Registration as follows:
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    Note
    Customer registration is the action that triggers the API call to the cloud, which transmits the new device configuration for the site. This will ensure the customer can see the updated site in their Tesla Mobile App, and the Partner(s) can see the correct device in Powerhub.
    1. On the Registration page, select Customer Registration.
    2. Enter the customer's email address.
      Informational PurposesAn informational icon, calling your attention
      Note
      Ensure the correct customer email is entered; this must be the email address the customer is using in their Tesla Mobile App to monitor their existing site.
    3. Select the "Suggested" site that appears. This action indicates that you are intending to register the new Powerwall 3 to the customer's existing site.
      Informational PurposesAn informational icon, calling your attention
      Note
      If you do not see a suggested site, it means that either:
      • The installer email address currently logged in to Tesla One is not associated with the installer instance for this site (this installer needs to have a Partner Portal account created with their email address)
      • The installer instance does not have access to the original site in Powerhub (see Site Sharing)
      • The customer email address is not the one that the customer is using to monitor their system in the Tesla App
    4. Select Register. This will submit the registration to the cloud, completing the final step in the on-site work.
  19. Start the system.
  20. Verify the following:
    • The system is on and operational
    • Solar is producing (if applicable)
    • The system is on-grid (and successfully displays off-grid during Backup Test)
    • All meters are reporting correctly
    • There are no errors or alerts present
  21. Explain to the customer the scope of work that was performed and ask them to verify they can see their system in their Tesla app. Confirm any remaining customer questions are answered before leaving site.

Confirm Site Updates in Powerhub

Once back in the office, confirm the site has been updated in Powerhub:
  • Confirm the new Powerwall 3 now appears in the Devices list in Powerhub
    • The new Powerwall 3 will appear instantly after registration
    • Note that Powerhub and the customer's Tesla App will not display data (telemetry or settings info) from the new Powerwall 3 right away. This data will appear after the overnight sync
  • Note that the old Powerwall 2 will still appear in the Devices list
    • Powerhub will consider these devices "Deactivated" after 30 days of no communication
    • Note that this will not impact the customer's app experience, telemetry, or ability to control their Powerwall 3
    • Once the 30-day period has passed and the Powerwall 2 device(s) are automatically deactivated, they will no longer appear in the Devices list in Powerhub