AUSTIN, Texas — Tesla just turned its two best-selling cars into backup generators. The company rolled out Powershare Home Backup for new Model 3 and Model Y vehicles paired with a Powerwall 3, letting them feed electricity back into a home during an outage — a capability that until now only the Cybertruck offered.
Tesla Energy says a Model 3 or Model Y can "extend your home backup by over 2 days," combining the car's battery with a Powerwall 3. The feature arrives in software update 2026.38.3 and needs no extra hardware: owners already set up with a Powerwall 3 and a Wall Connector 3 or Universal Wall Connector simply get it enabled over the air. It is the kind of quiet, software-delivered upgrade that keeps widening the gap between Tesla and rivals, much like the company's recent over-the-air performance improvements.
How Much Power
The numbers are substantial. With the grid down, the system delivers up to 11.52 kW of continuous power by combining the Powerwall and the vehicle. Tesla's "over two days" estimate assumes a home drawing 30 kWh per day with the car starting at 90% charge; standard trims are rated for up to two days, while the Cybertruck, with its larger pack, is rated for more than three.
On the vehicle side, the work is handled by a PCS2 Lite inverter. Lead engineer Wes Morrill explained the trickiest part was getting the car and the Powerwall to negotiate which device leads during an outage — a coordination problem across multiple hardware generations.
