The Tesla Powerwall 3 is an all-in-one home battery with a built-in solar inverter and system controller. It stores 13.5 kWh of usable energy, delivers up to 11.04 kW of continuous power on the UK grid, and expands to 54 kWh with Expansion units. Its solar-to-home efficiency is 97.5%.
Tesla Powerwall 3 Specifications (Full Spec Table)
Here are the full Tesla Powerwall 3 specifications for the UK, taken from Tesla’s official datasheet. Every figure below is the UK-market value, which matters because several UK numbers differ from the US datasheet that many sites quote by mistake.
| Specification | Figure |
|---|---|
| Usable capacity | 13.5 kWh |
| Nominal battery energy | 13.5 kWh AC |
| Depth of discharge | 100% (usable capacity equals nominal capacity) |
| Continuous power output (on-grid) | Configurable up to 11.04 kW (3.68 to 11.04 kW) |
| Backup power output | Up to 11.04 kW continuous; requires Backup Gateway 2 |
| Solar-to-battery-to-home/grid efficiency | 89% |
| Solar-to-home/grid efficiency | 97.5% |
| Integrated solar inverter | Yes |
| Number of MPPTs | 3 |
| Maximum solar input (STC) | 20 kW |
| Battery chemistry | Lithium iron phosphate (LFP) |
| Load start capability | 185 A LRA |
| Maximum charge rate | Up to 5 kW (single unit); up to 8 kW with Expansions |
| Scalability | Up to 3 Expansion units per Powerwall 3 (54 kWh). Up to 4 Powerwall 3 units plus 3 Expansions per system (94.5 kWh, 44 kW AC) |
| Dimensions | 1105 x 609 x 193 mm (43.5 x 24 x 7.6 in) |
| Weight | 130 kg (287 lbs) |
| Ingress rating | IP67 (battery and power electronics); IP55 (wiring compartment) |
| Enclosure rating | IP55 (indoor and outdoor rated) |
| Operating temperature | -20°C to 50°C |
| Mounting options | Floor or wall mount |
| Model number | 1707000-xx-y |
| Nominal grid voltage | 230 V AC, single phase |
| Grid frequency | 50 Hz |
| Grid connection standards | G98 / G99 |
| Monitoring | Tesla mobile app (Wi-Fi, Ethernet, cellular) |
| Warranty | 10 years, 80% energy retention at 10 years (UK), unlimited cycles |
Source: Tesla Powerwall 3 datasheet (UK). Every figure above is from that datasheet, except battery chemistry (lithium iron phosphate), which Tesla confirms across its Powerwall 3 materials rather than on this datasheet.
Download the Tesla Powerwall 3 spec sheet (PDF)
Thinking about a Powerwall 3 for your home? Get a free, no-obligation quote from an MCS-certified installer. Get a free Powerwall 3 quote or call 01789 262 411.
Tesla Powerwall 3 Usable Capacity
The Tesla Powerwall 3 has 13.5 kWh of usable capacity. This is Tesla’s official figure, listed on the UK datasheet as the nominal battery energy.
Usable capacity is the number that matters day to day, because it is the energy you can actually draw from the battery. Some batteries quote a larger “nominal” figure and then hold part of it back, so the usable total is lower. The Powerwall 3 does not do this. Its usable capacity and its nominal capacity are both 13.5 kWh, which means it runs at 100% depth of discharge. You get the full 13.5 kWh.
For most UK homes, 13.5 kWh covers a typical evening and overnight, roughly the amount an average household uses across a day. If your home uses more, you can add Expansion units, which we cover further down.
Tesla Powerwall 3 Power Output
The Tesla Powerwall 3 delivers up to 11.04 kW of continuous power on the UK grid. This is the headline UK figure, and it is worth explaining clearly, because you will see two different numbers online.
Tesla’s UK datasheet gives an output that is configurable from 3.68 kW up to 11.04 kW at 230 V, the standard UK single-phase grid voltage. The reason it is a range rather than a single number is that the output is set to match your grid connection and local network conditions during installation.
The 11.5 kW figure you may have seen comes from Tesla’s US datasheet, where the grid runs at 240 V. The datasheet also notes the unit can push up to 15.4 kW AC under specific higher-current conditions. For a UK home on a 230 V single-phase supply, 11.04 kW is the correct continuous figure to plan around. That is more than double the 5 kW continuous output of the Powerwall 2, so a single Powerwall 3 can run several demanding appliances at once.
Tesla Powerwall 3 Battery Chemistry (LFP)
The Tesla Powerwall 3 uses lithium iron phosphate cells, usually shortened to LiFePO4 or LFP. This is a change from the Powerwall 2, which used nickel manganese cobalt (NMC) chemistry.
LFP is a different trade-off, and it suits a home battery well. It runs at a lower risk of thermal runaway than NMC, so it is more stable and safer, which is part of why it can sit outdoors in a UK climate. It also holds up better over many charge and discharge cycles, so it degrades slowly. That longevity is why Tesla can back the Powerwall 3 with a 10-year, unlimited-cycle warranty, discussed below.
The practical result for you: a battery you can cycle every single day, charging from cheap overnight electricity or your solar panels and discharging in the evening, without wearing it out faster than the warranty allows. LFP is now the standard chemistry across most premium home batteries for exactly these reasons.
Tesla Powerwall 3 IP Rating & Weather Resistance
The Tesla Powerwall 3 is rated IP67 for its battery and power electronics, which means it is dust-tight and protected against temporary immersion in water. The wiring compartment is rated IP55. In plain terms, IP67 is a high level of protection: the “6” means no dust can get in at all, and the “7” means the sealed sections can withstand being briefly submerged.
That is why the Powerwall 3 can be installed outdoors in the UK. It operates across a temperature range of -20°C to 50°C, which comfortably covers British weather, from frosty winter mornings to the hottest summer days. Performance is de-rated above 40°C, but UK ambient temperatures rarely approach that.
Tesla Powerwall 3 Warranty
The Tesla Powerwall 3 comes with a 10-year warranty that, for UK installations, guarantees at least 80% energy retention at the 10-year mark, with unlimited charge and discharge cycles for everyday solar self-consumption, time-of-use and backup use. This is the figure published in Tesla’s official Powerwall warranty document for the European Warranty Region (Rev. 1.16, effective December 2025). That document sets the 80% threshold for the UK, Ireland and most of Western Europe, and reserves the lower 70% figure for Italy, Spain, Malta, Portugal and Slovenia only — so a UK page quoting 70% has applied the wrong regional number.
In practice, that means after ten years of daily use, Tesla guarantees the battery will still hold at least 10.8 kWh of its original 13.5 kWh. The unlimited-cycle part matters if you plan to charge and discharge every day on a smart tariff, because some rival warranties cap the total energy you can put through the battery before cover ends. Tesla’s does not. One condition: the Powerwall must stay connected to the internet so Tesla can send firmware updates, or the warranty can drop to four years.
On top of Tesla’s product warranty, we add our own 5-year workmanship warranty covering the quality of the installation itself. If a fault ever traces back to equipment, we handle the manufacturer warranty claim for you.
Tesla Powerwall 3 Expansion Pack: Scaling to 54 kWh
A single Tesla Powerwall 3 can take up to three Expansion units, which raises total usable capacity to 54 kWh. Each Expansion unit adds another 13.5 kWh of storage and sits behind the main Powerwall 3, sharing its inverter.
| Configuration | Total usable capacity |
|---|---|
| Powerwall 3 (1 unit) | 13.5 kWh |
| Powerwall 3 + 1 Expansion | 27 kWh |
| Powerwall 3 + 2 Expansions | 40.5 kWh |
| Powerwall 3 + 3 Expansions | 54 kWh |
If you need even more, whole systems can scale to four Powerwall 3 units plus three Expansions, for a maximum of seven units, 94.5 kWh of storage and 44 kW of continuous power. That is far beyond what most homes need, but useful for larger properties, homes with an electric vehicle and a heat pump, or small commercial sites.
Start with one Powerwall 3 and add Expansions later as your needs grow. Learn more on our Tesla Powerwall 3 Expansion Pack page.
What Is the Tesla Powerwall 3?
The Tesla Powerwall 3 is a fully integrated home battery that stores electricity, either from your solar panels or from the grid, for use when you need it. What sets it apart from earlier models is that it has a solar inverter and a system controller built inside the same unit.
That integration is the defining feature. A standard solar-plus-battery setup needs a separate solar inverter to convert the DC electricity your panels produce into the AC electricity your home uses. The Powerwall 3 puts that inverter inside the battery, so you do not need to buy and wall-mount a second box. Fewer components means a simpler installation, less wall space used, and often a lower total cost when you fit solar and storage together.
In everyday use, the Powerwall 3 stores surplus solar during the day, powers your home in the evening, and can charge from cheap off-peak grid electricity on a smart tariff. Paired with a Backup Gateway 2, it also keeps your home running during a power cut. You manage all of it from the Tesla app, which shows live generation, storage and usage. If you are weighing it against other batteries, our guide to comparing home storage batteries sets out the differences.
Tesla Powerwall 3 Inverter Specs: How Much Solar Can It Handle?
The Tesla Powerwall 3 has a built-in solar inverter that accepts up to 20 kW of solar (STC) across three MPPTs. Because the inverter is integrated, you do not need a separate solar inverter when you install panels alongside it.
An MPPT (maximum power point tracker) is the part of an inverter that manages a string of panels and squeezes the most energy out of it. The Powerwall 3’s three MPPTs let you connect panels facing up to three different directions, for example a south roof, an east roof and a west roof, and have each one tracked independently. That is genuinely useful in the UK, where many semi-detached and terraced homes have roof faces pointing different ways.
For a typical UK home, a solar array of 4 kW to 6 kW sits comfortably within the Powerwall 3’s 20 kW input ceiling, with plenty of headroom to add more panels later. Note that Tesla’s US datasheet lists six MPPTs; the UK datasheet specifies three, so three is the correct figure for a UK installation.
This is the biggest architectural difference from the Powerwall 2. The Powerwall 2 is AC-coupled and needs a separate solar inverter wired alongside it. The Powerwall 3 is DC-coupled with the inverter inside, which is why it is cheaper and cleaner to install as part of a new solar system.
Tesla Powerwall 3 Dimensions, Weight & Installation Requirements
The Tesla Powerwall 3 measures 1105 x 609 x 193 mm (43.5 x 24 x 7.6 in) and weighs 130 kg (287 lbs). It can be floor-mounted or wall-mounted, indoors or outdoors, and is rated IP67 for the battery and power electronics.
At 130 kg, the unit is heavy, so wall mounting needs a solid, load-bearing wall (brick or blockwork rather than plasterboard), and the fixings and bracket are sized for that weight. On floor mounts, the unit stands against the wall on its own base. Where you fit Expansion units, those stack behind the Powerwall 3 and must be floor-mounted.
A typical single Powerwall 3 install takes around a day when it is added to an existing solar system, and forms part of a two-day job when fitted alongside a new solar array. Every install is designed around your property first. We do not fit a standard package to every home; the position, mounting and system size are set to suit your building and how you use energy.
How Tesla Powerwall 3 Benefits Your Solar System
A Tesla Powerwall 3 lets you use far more of the solar energy you generate, instead of exporting the surplus cheaply and buying it back at a higher rate later. That single shift is where most of the savings come from.
Without a battery, solar panels only help while the sun is out. Any excess is sent to the grid, and in the evening you go back to buying electricity at full price. The Powerwall 3 stores that daytime surplus and releases it when you actually need it, in the evening and overnight. With its 97.5% solar-to-home efficiency, very little is lost in the process.
The benefits stack up in a few clear ways:
- Lower bills. You buy less electricity from the grid because you are running your home on stored solar and cheap off-peak power.
- Backup power. Fitted with a Backup Gateway 2, it keeps your essential circuits running during a power cut, automatically and within a fraction of a second.
- Smart tariff savings. On a time-of-use tariff, you charge the battery when electricity is cheapest overnight and use it during expensive peak hours.
- Export income. As an MCS-certified installer, our installations are eligible for the Smart Export Guarantee, so you can be paid for the surplus you do send back. See our Smart Export Guarantee guide.
The exact saving depends on your home, your solar array and your tariff, which is why we design each system around your usage rather than quoting a one-size-fits-all number.
How Long Will a Tesla Powerwall 3 Last in a Power Cut?
A single Tesla Powerwall 3 will typically run a UK home’s essential loads for around a day during a power cut, using its 13.5 kWh of usable storage. A home using roughly 8 to 10 kWh a day gets close to a full day of essential-load backup. Run heavier appliances and that time drops sharply.
The honest answer depends on what you keep running. Backup falls into two types. Essential-circuits backup keeps a chosen set of circuits alive, usually your fridge, freezer, lighting, broadband and a few sockets. Whole-home backup keeps everything on, which drains the battery much faster if you are also running high-power appliances.
Here is a rough guide to how long 13.5 kWh would power common appliances. These are estimates for a single appliance running on its own, to show the scale; in a real power cut you would run several at once, so treat them as indicative only.
| Appliance | Typical power draw | Rough runtime on 13.5 kWh (this appliance alone) |
|---|---|---|
| Broadband router | ~10 W | Several days |
| Fridge-freezer (averaged) | ~100–150 W | ~4 days |
| LED lighting (whole home) | ~100 W | ~5 days |
| TV | ~100 W | ~5 days |
| Washing machine (per cycle) | ~2,000 W | ~6–7 hours |
| Kettle | ~3,000 W | ~4–5 hours |
| Electric shower | ~9,000 W | ~1.5 hours |
The takeaway: your essential loads (fridge, freezer, lights, router, a few sockets) usually add up to a few hundred watts, so a full Powerwall 3 keeps them going for the best part of a day, sometimes longer. High-draw items like electric showers and ovens will run, but they use the stored energy quickly. If your home has high demand, a second unit or an Expansion adds backup time.
How Much Does a Tesla Powerwall 3 Cost in the UK? (2026)
A Tesla Powerwall 3 typically costs £7,000 and £8,000 fully installed with Stratford Energy, depending on your property and system design. That figure covers the unit itself plus installation; the exact price moves with a few factors.
What changes the price:
- Solar at the same time. Fitting the Powerwall 3 alongside a new solar array is usually more cost-effective per component, because the integrated inverter removes the cost of a separate one and the labour is shared across the job.
- Existing solar. Adding it to a system you already have can be simpler, or can need extra work depending on how your current setup is wired.
- Switchboard and consumer unit work. Some homes need electrical upgrades to add battery storage safely.
- Backup Gateway 2. Required if you want power-cut backup, and an added cost.
- Expansion units. Each Expansion adds capacity and cost.
- Siting. Longer cable runs, scaffolding or awkward mounting positions can add to the total.
On VAT: domestic battery storage in the UK currently qualifies for 0% VAT, whether installed with solar or on its own, under the government’s energy-saving materials relief. Crucially, this zero rate is time-limited: it runs until 31 March 2027, after which it is set to revert to a 5% reduced rate — so completing your installation before that deadline locks in the biggest saving. For a neutral market benchmark, the government publishes official battery installation statistics covering both capacity and cost.
Prices correct as of July 2026.
Want a real number for your home? Every quote is designed around your property, so we give you an accurate figure, not a guess. Get a free Powerwall 3 quote or call 01789 262 411. MCS · NICEIC · TrustMark · RECC accredited
Tesla Powerwall 2 vs Powerwall 3: What’s the Difference?
The main difference between the Powerwall 2 and Powerwall 3 is the inverter. The Powerwall 3 has a solar inverter built in and delivers more than double the continuous power; the Powerwall 2 needs a separate inverter and puts out less. Both store the same 13.5 kWh.
| Specification | Powerwall 2 | Powerwall 3 |
|---|---|---|
| Usable capacity | 13.5 kWh | 13.5 kWh |
| Continuous power output | 5 kW (7 kW peak) | Up to 11.04 kW (UK) |
| Integrated solar inverter | No (AC-coupled, separate inverter needed) | Yes (DC-coupled, inverter built in) |
| Maximum solar input | Depends on separate inverter | 20 kW across 3 MPPTs |
| Battery chemistry | NMC | Lithium iron phosphate (LFP) |
| Round-trip efficiency | ~90% round-trip (AC) | 89% (97.5% solar-to-home) |
| Dimensions | 1150 x 753 x 147 mm | 1105 x 609 x 193 mm |
| Weight | ~114 kg | 130 kg |
| Warranty | 10 years, 80% retention (UK) | 10 years, 80% retention (UK) |
Powerwall 2 figures are Tesla’s published specifications for that model, verified against Tesla’s Powerwall 2 datasheet.
Which suits whom? For most homes buying solar and storage together today, the Powerwall 3 is the better fit: the built-in inverter makes it cheaper and simpler to install, and the higher power output runs more appliances at once. The Powerwall 2 still made sense where a compatible inverter was already in place, but Tesla has moved its focus to the Powerwall 3, so new UK availability of the Powerwall 2 is limited. If you are choosing between batteries, our guide to choosing the right storage battery walks through it.
Is the Tesla Powerwall 3 Worth It?
For most UK homes with solar panels, the Tesla Powerwall 3 is worth it, because it lets you use far more of your own generation and cut what you buy from the grid. Whether it pays back in a timeframe you are happy with depends on your solar array, your tariff and how much you use in the evenings. Here is a balanced view.
In its favour:
- The integrated inverter reduces install complexity and cost when fitted with solar.
- Up to 11.04 kW of continuous power runs several demanding appliances at once.
- LFP chemistry gives long life, day-to-day cycling and strong safety.
- Full app control over charging, storage and backup.
- Expandable to 54 kWh as your needs grow.
Worth weighing up:
- The upfront cost is high compared with budget batteries.
- To get full value, it helps to have a reasonably sized solar array feeding it.
- At 130 kg it needs space, a solid mounting wall and proper clearance.
- On a single-phase home you may not draw the full continuous output in every scenario.
On payback: the savings come from three places, using stored solar instead of buying peak electricity, charging cheaply on a time-of-use tariff, and earning export income through the Smart Export Guarantee. Combine those and many homes see a return over the medium term, though a battery bought without solar and without a smart tariff will take longer to pay back. We would rather tell you that plainly than oversell it.
Is the Tesla Powerwall 3 Available in the UK?
Yes, the Tesla Powerwall 3 is available in the UK and is designed for the UK grid. It runs on a 230 V single-phase supply at 50 Hz and is certified to the UK grid connection standards G98 and G99.
A few points that come up often:
- Single-phase vs three-phase. The Powerwall 3 connects to a single-phase supply, which covers the large majority of UK homes. Its Backup Gateway 2 supports both single-phase and three-phase properties for backup.
- Grid connection. Any battery or solar install that connects to the grid needs your Distribution Network Operator (DNO) to be notified or to approve it, under G98 or G99. We handle that process for you.
- Existing solar. The Powerwall 3 can be added to many existing solar arrays. Whether it connects on the DC side (sharing its inverter) or the AC side depends on your current setup, which we assess before quoting.
- MCS and export. As an MCS-certified installer, our Powerwall 3 installations are eligible for the Smart Export Guarantee, so you can be paid for surplus energy. See our MCS certification explained and Smart Export Guarantee guides.
Why Choose Stratford Energy Solutions for Your Tesla Powerwall 3 Installation?
We are a local, MCS-certified installer based in Stratford-upon-Avon, and we have been installing solar and battery systems across the Midlands for 15 years. Our own in-house engineers carry out every install, not subcontractors, and many have more than ten years of individual installation experience.
What that means for your Powerwall 3:
- Every system designed around your home. We assess your roof, your usage and your property before we quote. No standard packages.
- Premium equipment only. We install Tesla Powerwall and other premium storage; we do not fit budget-grade kit.
- Real accountability. You deal with named people here, including Sales Managers Georgia Howson and Andy Hollis, not a national call centre.
- Aftercare that lasts. We monitor your system remotely through the Tesla app, back our work with a 5-year workmanship warranty, and handle any manufacturer warranty claim for you.
- Full protection. We are MCS, NICEIC, TrustMark and RECC accredited, so you have an independent dispute-resolution route and the credentials that back it.
We install across Warwickshire, the West Midlands, Gloucestershire, Northamptonshire and Oxfordshire, including Rugby, Leamington Spa, Coventry, Solihull and Stratford-upon-Avon. See our Tesla Powerwall 3 installation service in full.
Ready to see what a Powerwall 3 would do for your home? Get a free Powerwall 3 quote or call 01789 262 411 to talk to Georgia or Andy.
Tesla Powerwall 3 FAQs
How many kW is the Tesla Powerwall 3?
The Tesla Powerwall 3 delivers up to 11.04 kW of continuous power on the UK grid at 230 V. The output is configurable from 3.68 kW to 11.04 kW to suit your connection. The 11.5 kW figure some sites quote is Tesla’s US rating at 240 V.
How much solar can a Powerwall 3 handle?
The Powerwall 3 accepts up to 20 kW of solar input (STC) through its built-in inverter, spread across three MPPTs. That is far more than a typical UK home’s 4 kW to 6 kW array needs, so there is plenty of room to add panels later without a separate inverter.
Can the Powerwall 3 power a whole house?
Yes, paired with a Backup Gateway 2, the Powerwall 3 can provide whole-home backup, within the limit of its 11.04 kW continuous output. It can start heavy loads rated up to 185 A LRA. Very high simultaneous demand may need a second unit or essential-circuits backup instead.
Can the Powerwall 3 be installed outdoors?
Yes. The Powerwall 3’s battery and power electronics are rated IP67, meaning dust-tight and protected against temporary immersion, and it operates from −20°C to 50°C. That makes it suitable for outdoor wall or floor mounting in the UK climate, which is how many homes have it fitted.
What is the Powerwall 3’s model number?
The UK Tesla Powerwall 3 model number is 1707000-xx-y, as listed on Tesla’s UK datasheet. The Powerwall 3 Expansion unit is a separate product with its own model number, 1807000-xx-y.
What voltage does the Powerwall 3 run at?
The Tesla Powerwall 3 connects to a standard UK single-phase supply at a nominal grid voltage of 230 V AC, running at 50 Hz. This is the same voltage as your household mains, so it fits straight into a normal UK home electrical system.
What is the Powerwall 3’s charge rate?
A single Tesla Powerwall 3 charges at up to 5 kW. Add Expansion units and the maximum continuous charge power rises to up to 8 kW. That lets you top the battery up quickly from solar during the day or from cheap off-peak electricity overnight.
How many Powerwall 3 units can I install?
You can install up to four Powerwall 3 units plus up to three Expansion units in a single system, seven units in total, for a maximum of 94.5 kWh of storage and 44 kW of continuous power. Most homes need just one unit of 13.5 kWh.
Does the Powerwall 3 work without solar panels?
Yes. The Powerwall 3 can be installed as a standalone battery and charged from the grid, which works well on a time-of-use tariff where you store cheap overnight electricity for use at peak times. You get the fullest value, though, when it is paired with solar.