Powerwall 3 just got even more powerful
Introducing Expansion Packs - extra oomph for your battery
If you've already got a Tesla Powerwall 3, or you’re looking to get one, you can now add Expansion Packs to boost the amount of energy your system can store - without needing a whole second unit. That means double the power saved for when the sun goes down (or the grid goes dark).
We're a Tesla Powerwall Premium Certified Installer, and we’re now offering Expansion Packs:
- If you’re looking to get solar and a battery with us
- If you’re after a battery system on its own
- If you’ve already had solar installed and want to add a Powerwall 3
- If you've already got your Powerwall 3 fitted by us and want to add more storage
Just a heads up - if your Powerwall 3 was installed by someone else, we can’t add an Expansion Pack for you.
What is an Expansion Pack?
Think of it as a battery booster.
It’s a Powerwall 3 without the bits you don’t need twice (like the inverter). It connects directly to your current Powerwall 3 and each additional pack gives you 13.5 kWh of extra storage (that’s the same capacity as the Powerwall 3). So, with an Expansion Pack, you can bank more of your cleaner, cheaper solar energy - ready for when you need it.
Expansion Packs have the same height and width as a standard Powerwall 3, but are a little slimmer in depth, so they slot in neatly next to your existing unit. Up to three packs can be installed alongside a Powerwall 3.
Why add more storage?
☀️ Capture more solar
Don’t waste your rays
⚡ Use more of your own energy
Less reliance on the grid
💷 Cut bills
Store cheaper energy to use later (when prices are higher)
🔋 More backup
Stay powered up if the grid goes down
Do I need one?
The Powerwall 3 already provides 13.5 kWh worth of storage which is pretty impressive. But you might want to consider more, if:
- You regularly see your Powerwall 3 hit 100% before the day’s solar has ended
- You’re planning to add a heat pump or EV soon
- You’d like to store more off-peak electricity from the grid
- You want a bigger backup during power cuts
You can check your battery’s usage in the Tesla app or give us a call on 0808 196 6842 and we’ll help you think it through.
13.5 kWh goes a long way
With 13.5 kWh of extra storage you could power the average UK home for a full day or add up to 65 miles of EV range. See our workings
How much does it cost?
£4,200
If you’re installing an Expansion Pack alongside a Powerwall 3 during the same installation.
£5,599
If you’re installing the Expansion Pack to an existing Powerwall 3 battery.
Ready to expand?
If you don’t currently have solar panels or a battery and you’re looking to place an order, you can get started here.
If you’ve got solar panels or a Powerwall 3 already, select the battery only option below.
If you’d like to chat through your options, give our specialists a call on 0808 196 6842.
Frequently asked questions
What’s the difference between a Powerwall 3 and an Expansion Pack?
An Expansion Pack is just the battery - it connects to a Powerwall 3 and shares the same inverter and control system. It’s a more cost-effective way to add storage.
They both have 13.5 kWh storage capacity.
How big is it?
It’s the same height and width as a Powerwall 3 - just a bit slimmer in depth. Designed to sit neatly alongside the existing unit
Can I install an Expansion Pack myself?
Nope - it needs to be installed by a Tesla Certified Installer. (That’s us.)
How do I know if I need more storage?
Check the Tesla app. If your battery often hits 100% while the sun’s still shining, or you’d like to store more off-peak electricity, an Expansion Pack could be a smart move.
Planning to add a heat pump or EV?
If you're adding a heat pump or an EV charger, it’s worth checking if your battery can keep up. A Powerwall 3 Expansion Pack gives you extra storage to:
- Charge your EV using solar or off-peak energy
- Run your heat pump without relying on peak grid prices
- Future-proof your setup for smarter savings
I’ve got Powerwall 3 but not with Octopus – can I get one?
No, we’re only installing Expansion Packs to Powerwall 3 systems that we’ve installed ourselves.
Our claims explained
Power the average UK home for a day
Based on the UK average electricity usage of a typical home of ~3,900 kWh/year or ~10.7 kWh/day (Ofgem Typical Domestic Consumption Values, 2024).
Tesla Powerwall 3 Expansion Pack provides 13.5 kWh of storage which is more than the 10.7 kWh which is enough to power a typical home for a day.
Add up to 65 miles of EV range
Based on average EV efficiency of 4.8 miles per kWh (source: ZapMap, EV Database). Actual range will vary depending on vehicle model, driving conditions and efficiency.
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