Just like Powerwall 3, the DC expansion unit has an energy capacity of 13.5 kWh. However, it does not integrate some expensive components, such as an inverter, which makes it $1,000 cheaper than a regular Powerwall 3.
Powerwall 3 owners can add up to three expansion units to increase their system’s capacity. In such a setup, the original Powerwall 3 is responsible for power conversion, site control, and solar coupling.
