The Energy2 V3 Black — 17kWh of British-made battery storage. The highest capacity domestic battery in the UK. 15-year warranty. Installed in a single day.
15-year warranty · 0% VAT applied · Free survey, no obligation
Electricity costs as little as 7p/kWh overnight but up to 27p/kWh at peak. Your Energy2 battery charges when it's cheap and powers your home when it's expensive. The savings are automatic, every... single... day — for the next 20 years.
Your battery charges automatically during the cheapest off-peak hours — typically 12am to 5am at around 7p/kWh.
During the day, your home runs on stored energy instead of expensive peak-rate electricity at 27p/kWh.
Up to 75% off your electricity bill. £1,500–2,500 in annual savings after a 5–7 year payback period.
17kWh vs 13.5kWh. The highest energy density domestic battery available in Britain. And unlike Tesla, it's designed, manufactured and installed by British engineers — with a 15-year warranty, not 10.
17kWh of useable storage in a compact unit. Enough to power most homes for an entire day. Scale up to 272kWh with multiple modules.
12,000 cycles at 80% depth of discharge. LFP chemistry — the safest, most durable battery technology available. Fire-resistant by design.
Complete off-grid capability. When the power goes out, your lights stay on. Genuine energy independence for your home.
Works perfectly with existing or new solar panels. Store excess generation and use it when the sun goes down. Compatible with all major inverters.
Designed to work with heat pumps. Charge the battery at 7p/kWh and run your heat pump at a fraction of the cost — 4× more efficient than gas.
Engineered as repairable infrastructure, not a sealed appliance. If a component needs attention, we replace the part — not the entire battery.
| Energy2 V3 Black | Tesla Powerwall 3 | |
|---|---|---|
| Useable Capacity | 17kWh | 13.5kWh |
| Made in Britain | Yes — designed, built & installed | No — manufactured in USA/China |
| Warranty | 15 years | 10 years |
| Cycle Life | 12,000 cycles | ~6,000 cycles (25 years) |
| Off-Grid Capability | Full off-grid | Limited backup |
| Data Hosting | UK data centres | Tesla cloud (USA) |
| Serviceability | Component-level repair | Full unit replacement |
| Installation | 1 day, by our engineers | Varies by third-party installer |
| Inverter Compatibility | Victron, Sunsynk, Growatt, Solis | Tesla inverter only |
| Useable Capacity | 17kWh |
| Configuration | 16S1P |
| Nominal Voltage | 51.2V |
| Max Power Output | 10kW |
| Cycle Life | 12,000 @ 80% DoD |
| Chemistry | LFP (Lithium Iron Phosphate) |
| Dimensions | 82 × 41 × 27cm |
| Weight | 110kg |
| Communication | CAN port |
| Scalability | Up to 16 units (272kWh) |
| Warranty | 15 years |
| Certification | IEC 62619 and UKCA |
We survey your current and future energy usage and design a system around your property.
A detailed proposal with system design, projected savings and estimated payback period.
Our engineers install your system in a single day. No subcontractors. The same people who build it, install it.
Every home is different, so we provide a personalised quote after a free, no-obligation survey. This ensures you get an accurate price based on your actual energy usage and requirements, not a generic estimate. Our engineers will assess your property and recommend the right system for your needs. See our battery sizing guide for a self-service estimate. UK 0% VAT is applied automatically to residential installs.
Most domestic installations are completed within 48 hours. Our engineers handle everything from delivery to setup, testing, and activation. We'll agree a convenient time and keep disruption to an absolute minimum.
In most cases, no. Domestic battery storage systems are typically classed as permitted development. However, there are some exceptions for listed buildings and conservation areas. We'll advise you during your free survey if any permissions are needed.
Yes. We use Lithium Iron Phosphate (LFP) chemistry, which is the safest lithium battery technology available. LFP cells are thermally stable and do not experience thermal runaway. Our systems are fully certified to UK safety standards and carry MCS certification.
Our batteries are virtually silent in normal operation. Unlike some systems with active cooling fans, the V3 Black generates minimal noise that is unnoticeable in a typical home setting.
No. Our batteries work with or without solar. Many customers save significantly simply by charging from the grid during cheap off-peak hours (as low as 7p/kWh) and using that stored energy during expensive peak times (24p+/kWh). See our UK tariff guide for which Octopus tariffs work best with the V3 — including options for households without solar.
Our 15-year warranty is the longest in the UK domestic market. Because we design and manufacture our batteries in Britain, spare parts and servicing are always available. Unlike sealed imported units, our systems are designed to be serviced and maintained for decades.
Yes, our systems can be professionally relocated. We can arrange removal and reinstallation at your new property. A home battery also adds value to your property — energy efficiency improvements are increasingly attractive to buyers.
Book a free home survey and get a personalised quote. No obligation. No pressure. Just honest advice from the engineers who build them.
We don't publish prices online because every home is different. A free survey ensures you get an accurate, personalised quote — not a generic estimate.