Powerwall 3 specifications that matter in a UK home
These figures are from Tesla's 2026 UK datasheet and UK product page. The UK model is 230V single-phase, so several differ from the widely quoted US numbers.
| Specification | Powerwall 3 (UK) | What it means at home |
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| Usable energy | 13.5kWh per unit | Compare with other brands' usable, not nominal, capacity |
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| Power output | Up to 11.04kW; UK ratings run from 3.68kW (16A) to 11.04kW (48A) | Rating matched to your supply and grid connection |
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| Motor starting | 185A locked-rotor current | Starts heavy motor loads such as pumps |
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| Charging | Up to 5kW, or 8kW with Expansion units | Roughly three hours to fill on a cheap overnight rate |
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| Solar inverter | Built in: three MPPT inputs, up to 20kW of panels | New panels wire straight in; existing solar can keep its inverter |
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| Expansion | Up to four Powerwall 3s plus up to three 13.5kWh Expansion units, seven units in total | Add capacity later, to 94.5kWh |
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| Backup | Requires Backup Gateway 2 | Non-backup set-ups (Tesla Remote Meter) give no power in a cut |
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| Warranty | 10 years; 80% capacity at 10 years in the UK | Conditional, as below |
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Tesla's warranty applies to Powerwalls purchased from Tesla or a Tesla certified installer, and lists installation or commissioning by anyone else as grounds that may void it. The full ten years also needs the Powerwall kept online; otherwise Tesla commits to at least four. Tesla's warranty terms require a certified installer, so ask any installer to show their Tesla certification before you sign.
Powerwall vs Fox ESS and SolaX: honest fit
Powerwall 3 is the premium choice: 13.5kWh and a solar inverter in one unit, output that Tesla says covers whole-home backup in most homes, and the same Tesla app that runs a Tesla car if you drive one.
Fox ESS and SolaX are value storage: a hybrid inverter plus battery modules you buy in smaller steps and add to later. Our complete Fox ESS packages (panels, hybrid inverter and EP6 battery) start at £6,495 fully installed, less than our installed price for a Powerwall 3 on its own, and the EP12 upgrade is £995. Backup runs through the inverter's EPS output, so what it can carry depends on that inverter's rating and wiring.
Compare usable capacity, not headline figures: Fox ESS rates the EP12 at 11.52kWh nominal with a 90% depth of discharge, roughly 10.4kWh usable, against Powerwall 3's 13.5kWh usable.
- Choose Powerwall 3 to ride out power cuts with most of the house running, from one tidy unit.
- Choose Fox ESS or SolaX to keep the upfront cost down and grow storage in steps, with backup secondary.
We can price both; see every option on our battery storage page.
Install day and commissioning
Most installs take a full day on site, with the power off for part of it, longer if extra electrical work is needed.
- Siting: indoor and outdoor rated (IP67 battery and electronics, IP55 wiring compartment), −20°C to 50°C; at 130kg it needs a sound wall or floor mount.
- Gateway: for backup, Backup Gateway 2 fits between your meter and consumer unit so it can isolate the house in a cut.
- Grid connection: at the 3.68kW (16A) rating, with no other generation on site, it can go through G98 and be notified within 28 days. Higher ratings, or Powerwall alongside an existing solar inverter, exceed G98's 16A-per-phase limit, so G99 permission is needed before installation. Most Midlands homes are on National Grid Electricity Distribution's network.
- App set-up: Powerwall needs home Wi-Fi or Ethernet, not mobile data, as its main link; we set it up with you in the Tesla app.
- Warranty registration: you should be offered it at commissioning; keep the serial number, installation date and proof of purchase for claims. Our 2-year workmanship guarantee covers the installation.
Book a free survey to check siting, your supply and the grid route first.