Tesla Powerwall 3 + Expansion Pack
Double the storage on one inverter for heavy users and exporters.
Capacity
27 kWh (expandable to 54 kWh)
Power
11.04 kW
Warranty
10 years
Installed price
£10,500–£13,000
Overview
The Powerwall 3 Expansion is a battery-only DC unit (13.5 kWh) that connects to a Powerwall 3, adding capacity without a second inverter. The combined system delivers 27 kWh of usable storage on a single ~11 kW inverter, ideal for large homes, EV charging and heat pumps, or for banking a full day of cheap off-peak and surplus solar to sell back through the Smart Export Guarantee. A single Powerwall 3 takes up to three Expansion units (54 kWh); across multiple Powerwalls the system scales to 94.5 kWh.
Pros
- 27 kWh usable covers a full day for most homes, with headroom to export
- Shares the Powerwall 3's single ~11 kW inverter (no second inverter to buy)
- Expansion units are battery-only, so a lower cost per added kWh
- Whole-home backup for extended outages
Worth knowing
- High upfront cost
- Requires a Powerwall 3 as the base unit
- More capacity than a small home can usefully cycle
Best for
High-consumption homes and those banking surplus solar to export
Suits the Export & earn tier in our battery finder.
Technical specifications
Combined system (PW3 + 1 Expansion)
- Usable energy
- 27 kWh
- Continuous AC power
- Up to 11.04 kW (15.4 kW peak)
- Max per Powerwall 3
- 54 kWh (3 Expansions)
- Max system (multi-unit)
- 94.5 kWh / 44 kW AC
- Backup
- Whole-home (Backup Gateway 2)
Expansion unit
- Nominal energy
- 13.5 kWh
- Voltage range
- 52–92 V DC
- Chemistry
- LFP (LiFePO₄)
- Compatibility
- Powerwall 3 only
- Stacking
- Up to 3 behind a PW3 (floor mount)
- Operating temperature
- −20 °C to 50 °C
- Ingress rating
- IP67
- Dimensions (W×H×D)
- 1105 × 609 × 168 mm
- Weight
- 118.5 kg (with cover & bracket)
- Mounting
- Floor or wall
Certification
- Safety
- IEC 62619, IEC 62933-5-2
- EMC
- IEC 61000-6-1, EN IEC 61000-6-3
- Transport
- UN 38.3
Downloads
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Compare with Tesla Powerwall 3 + Expansion PackWant quotes for the Tesla Powerwall 3 + Expansion Pack?
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