Home Battery Storage

Cut your electricity bill by up to 65%.1

The Energy2 Black 17 — 17kWh2 of British-made battery storage. The highest capacity domestic battery module manufactured in Britain. 15-year warranty. Installed in a single day.

Design Your System How It Works
17kWh2
Per Module
15 yrs
Warranty
65%1
Bill Savings
1 day
Installation
Energy2 Black 17 home battery
How It Works

Charge cheap. Minimise peak.

Your Energy2 battery charges when it's cheap and powers your home when it's expensive. The savings are automatic, every... single... day.

🌙

Charge Overnight

Use a tariff like 100Green Tide Smart to charge your battery midnight to 7am at 7.43p/kWh3

☀️

Power Your Day

During the day, your home runs on stored energy instead of using the grid at a cost of 26.32p/kWh4

💷

Save Automatically

Cut your electricity bill by up to 65%.1

The Black 17

Overview

⚡

Highest Capacity

17kWh of storage in a compact unit — more than a typical UK home5 uses in a whole day. Scale up to 272kWh with multiple modules.2

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6,000+ Cycle Life

Rated for 6,000+ full cycles. LFP chemistry — the safest, most durable battery technology available. Fire-resistant by design.

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Full Off-Grid

Complete off-grid capability. When the power goes out, your lights stay on. Genuine energy independence for your home.

☀️

Solar Ready

Works perfectly with existing or new solar panels. Store excess generation and use it when the sun goes down. Compatible with all major inverters.

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Heat Pump Optimised

Designed to work with heat pumps. Charge the battery overnight and run your heat pump at a fraction of the cost — 4× more efficient than gas.

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Serviceable

Engineered as repairable infrastructure, not a sealed appliance. If a component needs attention, we replace the part — not the entire battery.

Head to Head

Energy2 vs Tesla Powerwall 3

Energy2 Black 17 Tesla Powerwall 3
Useable Capacity 16.9kWh2 13.5kWh6
Made in Britain Yes — designed, built & installed No — manufactured in USA/China
Warranty 15 years 10 years
Cycle Life 6,000+ 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
Specifications

Energy2 Black 17

Useable Capacity16.9kWh2
Configuration16S1P
Nominal Voltage51.2V
Max Power Output10kW
Cycle Life6,000+ (see Warranty Terms)
ChemistryLFP (Lithium Iron Phosphate)
Dimensions82 × 41 × 27cm
Weight110kg
CommunicationCAN port
ScalabilityUp to 16 units (272kWh)
Warranty15 years
CertificationSafety-Critical Components (Cells, BMS, Breaker): IEC 62619 Tested. System Design: Aligned to IEC 62619 (Limited Production Run)
Download Full Datasheet
Getting Started

Three steps to energy independence.

1

Free Home Survey

We survey your current and future energy usage and design a system around your property.

2

Personalised Quote

A detailed proposal with system design, projected savings and estimated payback period.

3

Installed in a Day

Our engineers install your system in a single day. No subcontractors. The same people who build it, install it.

Ready to cut your electricity bill?

Design your system in minutes, or book a free home survey. No obligation. No pressure. Just honest advice from the engineers who build them.

Design Your System Call 0800 112 6345
Made in Britain MCS Certified RECC Member IAA Member TrustMark

Important information

Important Note: The energy performance and benefits of EESS is impossible to predict with certainty due to the numerous functions a system can be programmed to perform.

You should not sign a contract based on specific energy prices. Tariffs vary between suppliers and can change, so these costs can go up or down.

  1. 1 Based on Ofgem's high-usage benchmark of 3,800kWh a year and the price cap for October–December 2026 (26.32p/kWh, 54.83p/day), against 100Green Tide Smart at 7.43p/kWh midnight to 7am, quoted for HP27 0SH in September 2026. Allows for 90% round-trip efficiency. Tide Smart is a variable tariff and rates vary by region. Your saving depends on your usage and tariff. ↩
  2. 2 See product datasheet ↩
  3. 3 100Green Tide Smart rates quoted for HP27 0SH on 9 September 2026: 7.43p/kWh 00:00–07:00, 34.63p/kWh at other times, 46.96p/kWh 16:00–20:00 weekdays, standing charge 54.14p/day. Tide Smart is a variable tariff; rates can go up or down and vary by region and supplier. ↩
  4. 4 Ofgem price cap unit rate for 1 October to 31 December 2026, national average. ↩
  5. 5 Based on DESNZ subnational electricity consumption statistics 2024 (Great Britain median 2,471kWh/yr, mean 3,323kWh/yr). Individual usage varies; winter daily use is higher than the annual average. ↩
  6. 6 Tesla Powerwall 3 usable battery energy (AC) of 13.5kWh per Tesla UK datasheet, checked September 2026. Energy2 figure is 16.9kWh DC guaranteed minimum after conversion to AC. Both figures are minimum guaranteed at beginning of life. ↩