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Marstek Venus E 3.0
Professional installation at no extra cost*
Affordable home battery storage — with or without solar.
I already have solarStore more of what you generate
I don’t have solarCharge on cheap, off-peak tariffs
See prices & installation
From
£1,499
Inc VAT
AWARD
2026
Emergency backup socketOne socket on the battery stays powered in an outage
Payback in as little as ~2.7 years*Based on 2 charge cycles a day — see terms below
Reserve with a 10% depositBalance due before delivery
5.12kWhScalable to 15.36 kWh
0%VAT on qualifying installs
IP65Weatherproof build
-20°CCold-rated operation
10yrWarranty
UK installation note: In the UK, Marstek batteries are hard-wired into a dedicated circuit at your consumer unit and wired to BS 7671 by a qualified electrician — never plugged into a household socket.
Installation & 0% VAT
Professional installation at no extra cost.
Qualifying residential battery installations carry 0% VAT until 31 March 2027 — so the VAT you’d pay on the battery on its own effectively covers our standard installation. Pick a size and see both prices side by side.
Most popular
Battery + professional installation
Battery£1,249
Standard installation£250
VAT£250£0*
Total installed£1,499
Same total price as battery-only
Payback in as little as ~2.7 years*
Get mine installed
*0% VAT applies to qualifying residential installations until 31 March 2027, so the VAT you’d pay on the battery alone effectively covers the standard installation cost. Payback estimate assumes 2 charge cycles a day — see full terms.
1ChoosePick your capacity with professional installation included.
2ConfirmWe check your setup and book a verified local installer.
3InstallHard-wired, commissioned and set up for you.
4Start savingStore cheap energy and use it when prices peak.
How it works in your home
Same battery, same installation. The only thing that changes is what it charges from.
Generate
Your existing solar panels generate power, exactly as they do today.
Store
Spare solar that would have been exported is stored in your Marstek battery instead.
Use
Your home runs on your own stored solar after dark, instead of buying it back at peak rates.
How does this work with my existing solar?Marstek is AC-coupled — it works alongside your existing solar, no inverter swap needed.
AC-coupled — nothing gets ripped out. Marstek works alongside your existing solar inverter. An energy meter spots spare solar and stores it in the battery, ready to power your home after dark — and it works without solar too, charging on cheap off-peak electricity.
Charge
The battery charges when your electricity tariff is at its cheapest, usually overnight.
Store
That cheap electricity is stored safely in your Marstek battery.
Use
Your home runs on stored electricity through the expensive peak hours.
Which battery is right for your home?
A few quick questions and we’ll do the maths.
1. Do you already have solar?
2. Roughly how much electricity do you use?
3. What do you want your battery to do?
Not sure? Don’t worry, we’ll confirm the right battery capacity before installation.
10.24kWh usable
We recommend
Venus E 3.0 · 10.24 kWh
Recommended for an average UK home, focused on lowering your electricity bills. Works alongside your existing solar.
From £3,450 Fully installed
£90 less than battery-only, professionally installed
Payback in as little as ~3.1 years*
Choose this battery
Choose your capacity
Own your energy from £1,499 Inc VAT. No small print.
Choose 5.12kWh, 10.24kWh or 15.36kWh. Buy battery only, or with quick professional installation, on almost any existing system.
Payback in as little as ~2.7 years*
Most popular
5.12kWh usable
Venus E 3.0 · 5.12 kWh
The one most flats and smaller homes start with.
£1,499Inc VAT
Same total price, professionally installed*
- 5.12 kWh usable — around 10 hours of essentials from the emergency backup socket
- AC-coupled — works alongside your existing solar
*Installed price includes standard installation. 0% VAT on qualifying residential installations until 31 March 2027. See full installation & VAT breakdown
*Payback estimate assumes 2 full charge/discharge cycles a day, a 16.5p/kWh difference between off-peak and peak electricity (8.5p charging vs 25p peak) and 90% round-trip efficiency — a best-case scenario. Most homes see fewer cycles and a narrower price difference in practice, so actual payback is typically longer. An estimate, not a guarantee.
See it in real homes
Quiet, tidy and out of the way — hard-wired, weatherproof and scalable, indoors or out.
Smarter energy, handled automatically
Marstek Intelligence reads live tariffs, weather and your usage to charge and discharge at the perfect moment, so you save without lifting a finger.
Works with Octopus Energy — sync your Venus battery with Octopus smart tariffs for automated time-of-use optimisation.
Available Soon
Coming Soon
Reputed Builders Merchant
Buy with confidence
Available directly from PowerXpress and through leading UK retailers. Real certification, a warranty that lasts, and friendly support from a UK-based team.
UK support
Friendly help before and after you buy, from a UK-based team.
Easy returns
Not right for your home? Return it within 30 days. Simple and stress-free.
10-year warranty
Built to last with a decade of cover and a 15-year design life.
UKCA & CE certified
Safe LiFePO4 cells
6,000+ charge cycles
15-year design life
iF Design Award 2026
Nationwide UK delivery, UK stock
For UK electrical & solar installers
Join the PowerXpress Verified Installer Network.
Receive installation opportunities generated through PowerXpress, together with product training, trade pricing and technical support.
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Installer & wholesale rates
Better pricing than retail, with volume discounts as you scale.
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Healthy margins
A fast-selling battery storage product your customers already want.
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UK stock & support
Reliable supply and a UK-based team behind every order.
Technical specifications
Venus E 3.0, 5.12 kWh AC-coupled home battery. Scalable to 15.36 kWh.
Usable capacity5.12 kWh
Scalable to15.36 kWh
Cell chemistryLiFePO4
Nominal voltage51.2 V
Rated power2,500 W
Max power (3 units)7,500 W
Cycle life6,000+ cycles
Round-trip efficiency>93.5%
Protection ratingIP65
Operating temperature-20°C to +55°C
Dimensions (H×W×D)620 × 480 × 160 mm
Warranty10 years
Questions, answered simply
UK installations are hard-wired for full compliance and warranty cover, so we recommend our quick professional installation service, usually done in a single visit. Thanks to 0% VAT on qualifying installations, it can cost around the same as buying the battery alone.
No. UK installations through PowerXpress are hard-wired into a dedicated circuit at your consumer unit, with its own isolator switch, and wired to BS 7671 by a qualified electrician — never plugged into a household socket. The battery does have a separate emergency backup socket, which can continue powering suitable appliances during a power outage, subject to the available battery capacity and the socket’s power rating.
The Venus E has a dedicated emergency backup socket on the battery itself. If the grid goes down, that one socket stays powered, so you can plug in essentials such as a fridge, router, lamp or phone charger. This is not whole-home backup — a standard installation does not keep the rest of your circuits running. What you can run, and for how long, depends on the battery’s power rating and how much charge is left in it at the time.
Yes. It works alongside almost any existing solar panels or home energy system, and it also works perfectly well on its own if you do not have solar yet.
If it is not right for your home, return it within 30 days for a refund. Full returns details are provided at checkout and with your order.
Every Venus E comes with a 10-year warranty. The battery uses safe LiFePO4 cells rated for more than 6,000 charge cycles and a 15-year design life.
You store cheaper off-peak electricity and use it during the expensive peak hours, and store any spare solar instead of exporting it. Your exact saving depends on your tariff and usage.
Stop renting your energy. Own it.
Store cheap power, beat peak prices, and take back control of your bills. Buy it, get it professionally installed, backed by a 10-year warranty.
From £1,499 Inc VAT
Trusted UK resellers · Clear pricing · Easy returns
