Homeowner Blog

Tesla Powerwall 3 - How Does it Compare to Powerwall 2?

Alicja Kopinska · 18 Jun 2024



Tesla's Powerwall has been a game-changer in the residential energy storage market, and the brand new Powerwall 3 promises to take it to the next level. Here's a detailed comparison between the Powerwall 2 and the highly anticipated Powerwall 3:


Powerwall 2

Powerwall 3

Usable capacity

13.5 kWh

13.5 kWh

Continuous power output

3.68 kW or 5 kW

3.68 kW - 11.04 kW (wide range of ratings available)

Round-trip efficiency




Tesla app

Tesla app


10 years

10 years


Wall- or floor-mounted and can be stacked

Wall- or floor-mounted

Location & Weather Resistance

Indoor or outdoor installation - water-resistant

Indoor or outdoor installation - Flood and dust resistant

Operating Temperature

-20°C - 50°C

-20°C - 50°C, Active Thermal Management


H 1150 mm x W 753 mm x D 147 mm

H 1,098.6mm x W 609.6mm x D 193.04mm




MPPT strings

N/A - No solar inverter.



Up to 13.5kWh max addition per unit; Powerwalls can be stacked

Up to 54 kWh per unit with 3x DC expansion packs.


Powerwall 2 currently costs £7100 when installed with or without solar.

Powerwall 3 starts at £7950 when installed by itself, however, when installed with solar PV, Powerwall 3's price can come down by up to £1,500 due to labour and inverter savings. There are 2 reasons for such a large price drop. The first is that less labour is required as installers are already on-site for the PV installation and they can help with the battery installation. The second reason is that you save on the solar inverter, which costs ~£500 - £700, depending on the model. 

If you're looking at solar PV as well, then it's certainly worth looking at Powerwall 3.

Storage Capacity

Both the Powerwall 2 and Powerwall 3 offer a storage capacity of 13.5 kWh, which is ample for most residential needs. However, the Powerwall 3 can be expanded up to 54 kWh by adding three additional 13.5 kWh expansion units, providing more flexibility for larger energy demands. The expansion units are cheaper than adding an additional Powerwall 3 as they don't need to contain certain technologies like the solar inverter etc...

The 13.5 kWh number isn't random, Tesla conducted a lot of research and worked out that 13.5 was the right amount of storage for most households.

Power Output

The Powerwall 2 has a continuous AC power output of 5 kW. In contrast, Tesla's Powerwall 3 boasts a significantly higher continuous AC power output of up to 11.04 kW. This increased power output means the Powerwall 3 can handle higher load requirements, making it better suited for whole-home backup during power outages. The inverter can be set to any of the below ratings, so you don't need to have it set to 11.04kW if it isn't necessary.

The Tesla Powerwall 3 hybrid inverter can be set to any of the following ratings: 3.68 kW, 5 kW, 6 kW, 7 kW, 8 kW, 9 kW, 10 kW, 11.04 kW.

Integrated Solar Inverter

One of the key differences between the two models is that the Powerwall 3 features an integrated hybrid solar inverter. This all-in-one design simplifies installation and communication between the solar panels and the battery. The Powerwall 2, on the other hand, requires a separate solar inverter. An integrated "hybrid" inverter allows you to save on both the kit cost and installation time because you don't need to pay for a dedicated solar inverter. This was always the weak point of Powerwall 2 in the UK.

AC/DC Coupling

The Powerwall 2 is an AC-coupled system, while the Powerwall 3 can be either DC or AC-coupled. DC coupling offers higher efficiency, with the Powerwall 3 boasting a round-trip efficiency of 97%.

Octopus Intelligent Integration

Tesla Powerwall 3 can integrate with Octopus Intelligent tariffs like Octopus Intelligent Flux. This allows you to optimise savings as the Powerwall will communicate with your Octopus Intelligent tariff to charge and discharge at the most profitable times.

Backup Capabilities

Both the Powerwall 2 and Powerwall 3 require the Tesla Gateway to enable backup power during grid outages. However, the Powerwall 3's higher power rating makes it better suited for whole-home backup. To enable backup power for essential circuits during a grid outage, you must still purchase the Tesla Gateway device, which acts as a "gateway" between the Powerwall and the home's electrical system.

Dimensions and Weight

The Powerwall 3 has a more compact design, measuring 1098 x 609 x 193 mm, compared to the Powerwall 2's dimensions of 1150 x 753 x 147 mm. 


Both models come with a 10-year warranty, guaranteeing that at least 80% of the cell capacity is still there after 10 years. There is a Tesla help and support line opening up in the UK.

Should I upgrade from Powerwall 2 to 3?

Tesla Powerwall 3 offers significant upgrades in continuous power output (11.04 kW vs 5 kW), load start capacity (185 A vs 106 A), integrated inverter, EV charger support, and an outstanding maximum solar DC input of 20 kW. If your household has high energy demands exceeding 5 kW continuous load, frequently needs to start large motor loads like air conditioners, plans to expand your solar array substantially, or wants an integrated EV charger solution, then upgrading to the Powerwall 3 could provide substantial benefits.

If your existing Powerwall 2 meets your backup needs and you don't require the higher power output or solar capacity, the upgrade may not be worth the cost since both models share the same 13.5kWh energy capacity and 10-year warranty.

In summary, while the Powerwall 2 remains a reliable and capable energy storage solution, the Powerwall 3 offers significant upgrades in power output, integration, and efficiency. However, the choice between the two will ultimately depend on your specific energy needs, budget, and installation requirements. 


Topics: Battery storage, Tesla Powerwall