If you’re planning a solar upgrade and want to future-proof your home, the Tesla Powerwall 3 Expansion Pack is one of the smartest investments you can make.  It adds modular, affordable storage to your existing Tesla Powerwall 3 system, giving you more energy independence, more flexibility, and the best cost-per-kWh storage on the market.

Delivered by Naked Solar’s in house Tesla Premium Certified installation team, the Expansion Pack is designed to make growing your system simple.  Here’s everything you need to know.

 

What is the Tesla Powerwall 3 Expansion Pack? 

The Expansion Pack is a DC-coupled add-on battery that boosts your Tesla Powerwall 3’s storage by 13.5 kWh. Unlike a full Tesla Powerwall 3 system, it doesn’t need its own inverter – instead, it connects directly to your Tesla Powerwall 3 to increase capacity at a lower price.

You can add up to three Expansion Packs per Tesla Powerwall 3 to give you a whopping 54kWh of storage and no need for a Grid Connection application.  Larger systems can be created by linking multiple Powerwall units together.

Looking at Solar for the first time?  Start with Naked Solar’s Solar PV overview to see how panels and batteries work together.

The Tesla Powerwall 3 Expansion pack makes more of your self generated solar energy with an increased charging power from 5kW to 8kW, meaning less of your energy will spill over to the grid.

 

Why the Expansion Pack Makes Sense 

Affordable Storage 

One of the biggest advantages of the Expansion Pack is value. At £444 per kWh of storage, it offers the lowest cost per kWh on the UK market.  That makes it a more economical choice than adding a second full Tesla Powerwall 3.

Scalable & Flexible

Whether you’re getting an EV, adding a heat pump, or seeking energy security as grid prices soar, the Tesla Powerwall 3 Expansion Pack lets you expand step by step. 

Seamless Integration 

Tesla Powerwall 3 Expansion pack is plug and play, taking a couple of hours to install and bolting on to your existing Powerwall 3.  With no DNO (National Grid) application required, you’re free to increase your storage and power unrestricted.  

Reliable backup

Tesla Powerwall 3 Expansion Packs extend your runtime during powercuts maintaining normal service for longer.  Want to consider all Solar Battery Storage options?  Explore Naked Solar’s “6 Watts? of Solar Storage” for an overview and comparison of all the UK’s most popular Solar Battery Storage Solutions.

Improved Energy Security 

Storing more of your clean energy generation increases energy independence and shields you from future energy price hikes. 

 

The Expansion Pack Units can be stacked behind or mounted next to the main Tesla Powerwall 3 Unit.

 

How It Works with Tesla Powerwall 3 

The Tesla Powerwall 3 handles the power conversion and system management.

Tesla Powerwall 3 Expansion Pack simply adds extra capacity and power to deliver:-

• Capacity: +13.5 kWh per Expansion Pack.
• Maximum per unit: 3 Expansion Packs (up to 54kWh).
• System scaling: Multiple Powerwalls + Expansion Packs can be linked for even larger systems.
• Output power: Maintains 11kW of continuos power for longer.
• Charging power: Increased from 5kW to 8kW – capture more of your precious self-generated energy.

 

Who Should Consider the Tesla Powerwall 3 Expansion Pack?

The Tesla Powerwall 3 Expansion Pack is ideal for:

• Families with high energy needs (multiple appliances, EV charging, heat pumps). 
• Solar customers wanting to maximise self-consumption, reduce grid reliance or increase Solar Grid Trading revenue.  
• Homeowners planning upgrades – add capacity now or later as your lifestyle changes. 
• Anyone seeking peace of mind with longer backup during power cuts. 

 

Ready for your Expansion pack from a Tesla Premium Installer?

Because the Expansion Pack is designed to integrate directly with Tesla Powerwall 3, installation is straightforward and cost-effective. Our Premium Tesla-certified team handle everything neatly and efficiently. 

• Cost per kWh: Adding a Tesla Powerwall 3 Expansion pack means you’re adding extra storage at an industry defying £444 per kWh – the lowest Solar Storage price on the UK market. 
• System costs: Depend on your current setup, how many Expansion Packs you choose, and whether you’re combining with new solar panels each Expansion pack is £5209 installed.

 

Rewarded with the coveted “Tesla Powerwall Premium Certified Installer”, Naked Solar are proud to be in the top 3% of UK Powerwall Installers.  A symbol of trust from Tesla based on installation quality checks and customer feedback.

 

FAQs 

Can I add an Expansion Pack later?
Yes. You can start with a Tesla Powerwall 3 and retrofit Powerwall 3 Expansion Packs in the future.

Does the Expansion Pack increase output power?
No – it increases storage capacity only. The Tesla Powerwall 3’s built in inverter is already capable of 11kW output, plenty for the vast majority of domestic needs.  If more power is required then multiple Tesla Powerwall 3s can be installed.  The Tesla Powerwall 3 Expansion pack increases charging power from 5kW to 8kW, meaning less of your solar generation will spill over to the grid. 

How many Powerwall 3 Expansion Packs can I add?
Up to three per Tesla Powerwall 3.  For larger systems, multiple Tesla Powerwall 3s can be linked to create a powerhouse of energy storage.

Will it affect my warranty?
No. The Expansion Pack is covered by Tesla’s standard 10-year warranty, the same as the Tesla Powerwall 3.

 

Lower Your Costs Today With the Tesla Powerwall 3 Expansion Pack 

The Tesla Powerwall 3 Expansion Pack is a smart, modular way to grow your home energy system. With the lowest cost per kWh in the UK, it’s a future-proof solution for households who want to make the most of their solar power and enjoy greater independence from the grid.

Start by exploring our Solar PV options or get full details on the Tesla Powerwall 3.

If you have any further questions or are ready to take the first steps, our award-winning team are ready to help you find the perfect system for your home and desires.

 

Talk Battery Storage With Our Award Winning Team