Is Powerwall 3 compatible with Powerwall 2?

Tesla has launched Powerwall 3, their latest home battery storage system, which features a higher power output and integrated solar inverter. While it still offers 13.5kWh of storage, just like Powerwall 2, there are some key differences that impact compatibility. 

Key Differences Between Powerwall 3 and Powerwall 2

  • Integrated Inverter: Powerwall 3 combines a DC inverter and battery in one, allowing it to accept up to 20kW of solar panels. In contrast, Powerwall 2 is AC-coupled and requires a separate inverter.
  • Power Output: Powerwall 3 offers a continuous output of 5kW, 10kW, or 11.5kW,(1) depending on configuration, whereas Powerwall 2 provides a fixed 5kW output. Continuous output refers to how much power the battery can deliver at any given time.
  • Battery Efficiency: Powerwall 3 has a slightly lower round-trip efficiency (89%) compared to Powerwall 2 (90%), meaning slightly more energy is lost when charging and discharging.

Given these differences, if you already own a Powerwall 2, you might be wondering if you can add Powerwall 3 to expand your energy storage capacity. Let’s explore why this isn’t possible.

Why Can't Powerwall 3 Be Added to Powerwall 2? 

Unfortunately, Powerwall 2 and Powerwall 3 cannot be installed together due to three main reasons:

  • Different Electrical Configurations: Powerwall 2 is an AC-coupled battery, meaning it works with an external inverter. Powerwall 3, however, has a built-in DC inverter, allowing it to connect directly to solar panels. This fundamental difference prevents them from working together.
  • Incompatible Software & Firmware: Each Powerwall model runs on a different firmware and software system, making integration infeasible.
  • Battery Technology: Powerwall 3 uses Lithium Iron Phosphate (LFP) whereas Powerwall 2 relies on Lithium-ion technology. LFP batteries are cobalt-free, making them less likely to overheat.

What If You Already Own Powerwall 2?

If you want to expand your energy storage, the best option is to add another Powerwall 2 unit while they are still available. However, Tesla has announced plans to phase out Powerwall 2, and stock may only last until early-to-mid 2025.

Your local Solahart Dealer can help determine if adding another Powerwall 2 is the right choice by:

  1. Assessing your current energy usage: Do you regularly use all the stored energy from your Powerwall 2? Would extra capacity help reduce reliance on the grid? Do you live in an area prone to blackouts?  
  2. Considering your future energy needs: Will your energy consumption grow in the coming years? If you plan to get an electric vehicle or expand your household, adding extra storage now could be a smart investment..

Also read: Should I install a solar battery? Six factors to consider

If you require more energy storage capacity and Powerwall 2 is no longer available, you will need to replace your existing units with Powerwall 3, which may be a more expensive option in the long run. Hence, it would be more cost-effective to assess your needs now and add more Powerwall 2 units as soon as possible.

Plan Ahead – Act Now

If you are considering expanding your battery storage, now is the best time to act while Powerwall 2 is still available.

Contact Solahart today at 1300 721 984 or enter your details below to book a free in-home assessment.

Get in touch with Solahart

Contact Solahart today at 1300 721 984 or enter your details below to book a free in-home assessment.

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Important Note: Powerwall 3 accommodates a maximum of 5kW output in Western Australia due to local regulations.