Battery only installs: a transparent UK price comparison
This blog post aims to give an overview of domestic battery-only installation costs and the options available across the UK market in February 2026. We include our own pricing in the same comparison charts for transparency and completeness, but the overall aim is to provide an honest, clear overview of the current options we could find in a growing and rapidly evolving industry and marketplace.
The battery storage market is changing fast. In this review we did what we’d do if buying one ourselves: gathered installed prices from a range of suppliers and installers, calculated a simple £ per kWh, and cross-checked quotes against basic warranty terms to make a fair and transparent apples-to-apples comparison.
We then considered the cost of a DIY battery install. Read on to find out how EquiVolt compares.
Suppliers & sources we used:
We prioritised supplier and installer webpages that display clear “fully installed” pricing (rather than relying on forum posts or blog entries, which can be outdated or difficult to independently verify). Where the market does not publish direct installed prices, we have taken the advertised ‘from’ prices as the best‑case scenario and used those figures in our comparison.
Many suppliers refused to provide a quote without conducting a home visit first. We didn’t intentionally aim to exclude them from our comparison — and we would always encourage people to obtain a minimum of three to five quotes before committing to a home storage system. With any large purchase, it’s worth taking the time to be fully informed before you commit.
Installed system prices used in our comparison have been sourced from: Octopus Energy, ITS Technologies, CRG Direct, Aspect Group Services, Heatable, Always Off-Peak, (all comparison prices are from Febuary 2026).
How we calculated “£ per kWh” for comparisons
and why it’s not the whole story…
£/ usable kWh = Total Installed Price (£) ÷ Stated Usable Battery Capacity (kWh).
Usable capacity is key, since batteries often have a larger nameplate capacity than what is actually accessible to the user. For example, an EquiVolt 15 kWh system carries a nameplate capacity of 16.1 kWh, but only 15 kWh is accessible for everyday use. In this blog we have only considered the published usable capacity not the nameplate capacity.
Usable capacity is a useful metric when comparing the costs of battery-only systems, but we recognise it does not tell the whole story: two systems with the same stated usable capacity (kWh) can perform very differently in real-world use.
Power (kW) vs Energy (kWh):
Think of a home battery system like a water tank + a tap.
Battery = the water tank (how much water you can store)
Measured in kWh, like a tank’s litres, this is the Energy.
Inverter = the tap and pipework (how fast you can deliver water)
Measured in kW, like litres per minute, this is the Power.
A big tank doesn’t automatically mean you can get a powerful shower—that depends on the tap size.
If your tap is small (small inverter), you can still have a huge tank (big battery), but you’ll only ever be able to “pour” electricity out slowly.
Result: it runs loads gently, but it can’t cover big peaks.
If your tap is large (big inverter) but your tank is small (small battery), you can blast out lots of power… but only for a short time.
Result: it handles peaks well, but the battery empties quickly.
An example to bring this to life:
10 kWh battery + 3.68 kW inverter
That system can supply up to 3.68 kW at any moment, so it could run: lights + fridge + TV + broadband + a small kettle but not a big combined peak.
And in duration terms:
If you’re drawing the full 3.68 kW, a 10 kWh battery lasts about 10 ÷ 3.68 ≈ 2.72 hours.
5 kWh battery + 6 kW inverter
Great “tap”, small tank — you can run heavy loads, but at 6 kW it lasts 5 ÷ 6 ≈ 0.8 hours (about 50 minutes).
The same logic is key for fully charging a battery system on time-of-use tariffs. If your selected tariff only offers 5 hours per night of off-peak electricity and your inverter is G98 approved (3.68 kW), then the theoretical maximum battery capacity you could charge during that window is 18.4 kWh (3.68 kW × 5 h = 18.4 kWh)*.
*In reality charging incurs efficiency losses when converting AC to DC, as well as other system losses, so the practical usable fill is closer to 15 kWh.
System power rating is therefore crucial and strongly affects performance. Considering how critical system power is in influencing the overall performance in this post we have only compared systems with the same inverter sizes. As EquiVolt currently only offers G98-compliant 3.6kW inverters, this review only compares similar systems.
Other considerations for a fair comparison:
Backup capability
We don’t see whole-house backup as essential in the UK because the grid is very stable (see our whole house back up blog) So this post won’t cover backup options in detail, and the systems we compare don’t need that feature to be included.
DNO paperwork
Any system that can export electricity to the grid (even if you don’t plan to) needs DNO approval in the UK. For this review we only included installations that include DNO G98 paperwork.
Warranty duration & conditions
With any large purchase, a warranty should be provided, but not all warranties share the same duration or terms. In this blog we will call out two key aspects of the warranty and for systems to be included in our comparison they need to provide:
10 Year minimum warranty duration
70% depth of discharge capacity at end of warranty period
Professional installation
Price must include professional installation to be considered in our review. As a minimum this means an Electrical Installation Certificate and compliance with building regulations. Adding an inverter/battery on a new dedicated circuit in a UK home is notifiable work, so professional installation is required no matter who you hire.
MCS certification
EquiVolt currently isn’t providing MCS certification because our products are designed to be portable, and MCS requires equipment to be geographically fixed. For that reason we have excluded MCS certification as a requirement in this comparison.
Battery storage prices £/kWh installed UK
Prices have all been taken at a system size that is as close to an EquiVolt offering as possible, all systems in the review include professional installation, warranty, DNO paperwork and a minimum inverter size of 3.68kW. The average price is > £375 per kWh.
How does EquiVolt compare?
EquiVolt has a key difference: we don’t bundle 10 years+ of app and server support into the up-front cost.
We also operate on a clear cost-plus pricing regime. We’re not watching the rest of the market to set our prices — we simply look at our actual costs and add a modest margin. If our costs go up or down, our retail prices will follow accordingly; it’s straightforward and transparent business.
When you buy an EquiVolt system you own the hardware at near‑cost price and then have the option to subscribe to the software separately as an ongoing service. EquiVolt+ is our smart decision engine that maximises battery life, boosts savings, and optimises your home energy use, and you can subscribe for £6 per month. There are no long‑term contracts, and we’re perfectly happy if you prefer to self‑manage, self‑integrate, or even choose to develop your own smart controller!
With EquiVolt, you own everything outright from day one, and you'll never be locked into long-term contracts or ongoing commitments.
As this post is focused on making fair, transparent comparisons, we should also include the EquiVolt+ cost over a 10-year period so we align with the rest of the market that bundles this into the initial installation expense.
The total EquiVolt 15kWh system ownership fee would therefore be:
Installation fee = £3,000
10 Year of EquiVolt+ Subscription, £6 x 12 x 10 = £720
Total = £3720 (or £248/kWh)
If you do choose to self-manage or build your own smart controller, the price improves further to just £200/kWh [£3000 for 15 kWh]. This is roughly 40% below the current market average, based on our review.
What about DIY battery storage?
DIY storage is quickly becoming mainstream in the UK, and we think that is fantastic — the more households that adopt it, the greater the improvement in grid flexibility and resilience for everyone.
Costs for projects like this are also highly competitive; an example of a representative project bill of materials is outlined below:
Fogstar ECO 16.1kWh battery - £1850 including standard UK delivery costs
Afore 3.6kW Inverter (G98 compliant hybrid inverter ) - £650 including standard UK delivery costs
Isolator switches, cable, mounting brackets etc. ~ £120
Professional connection to MCU and completion of electrical installation certificate ~ £200-250
DNO G98 notification - £0 but time and effort required to navigate the system
Installation time & effort - £0
Monitoring apps and data-stream set up - £0
System commissioning & troubleshooting - £0
Total = £2870
That is a great price, and honestly it’s achievable for people who are willing to complete complex DIY tasks. If you’re up for the challenge we are also happy to share advice and help you out where we can.
As you can see, the ~£150 saving compared to an EquiVolt system of the same capacity clearly demonstrates that our margins remain modest and carefully managed.
Want us to review a quote or have further questions?
We’re always happy to review other quotes and offer honest advice — if you have an alternative quote to discuss, feel free to post it in the comments below or send an e‑mail to us at hello@equivolt.co.uk