Home batteries and backup

How Much Rooftop Solar Can Connect Directly to a Tesla Powerwall 3?

Published September 23, 2026 · By the SolarPanelX editors · Prices and specs as of that date, from the pages under Sources

Summary

Up to 20 kW of solar (STC rating) per unit, across six MPPT inputs. Powerwall 3 has a solar inverter built in, and each unit delivers up to 11.5 kW of AC to the house, so it accepts more panel capacity than it puts out. At 400 W per panel, 20 kW is 50 panels.

The solar side of the spec sheet

Tesla's Powerwall page says each unit is "self-contained with an integrated solar inverter," and the 2025 datasheet calls Powerwall 3 "a fully integrated solar and battery system." The U.S. installation manual's spec table, last modified April 3, 2026, gives these figures:

Spec	Value
Maximum solar STC input	20 kW
PV DC input voltage range	60 to 550 V DC
PV DC MPPT voltage range	60 to 480 V DC
MPPTs	6
Maximum current per MPPT (Imp)	15 A on units labeled 15 A; otherwise 13 A
Maximum short-circuit current per MPPT (Isc)	19 A
Nominal AC output settings	5.8, 7.6, 10, or 11.5 kW
Nominal battery energy	13.5 kWh (25°C, beginning of life)

For high-current panels, the table allows a jumper that combines two MPPTs into one input taking up to 30 A Imp and 38 A Isc.

Adding units

There are two ways to grow a system. Up to four Powerwall 3 units can be combined, and up to three battery-only Expansion units (13.5 kWh each, compatible only with Powerwall 3) can be added, for seven units in all. Expansion units have to connect to the Leader Powerwall 3 and will not function behind a Follower. Seven units at 13.5 kWh add up to 94.5 kWh.

More battery also means faster charging. A Powerwall 3 alone charges at 20.8 A AC, or 5 kW; with up to three Expansion units the figure rises to 33.3 A AC, or 8 kW. If the unit is set to its 11.5 kW on-grid rating and installed with an 80 A breaker, an option allows up to 15.4 kW of discharge off-grid when solar is available. The warranty is 10 years.

Shopping for one? Browse home backup power stations →

Sources

We have not tested these products. Specs, prices, stock and terms are as published on these pages on the date above and can change; check the manufacturer or retailer before you buy.

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