Battery shop price vs installed price: why they differ
Search for a battery price and half the results are shops listing batteries as boxes. Those prices answer a different question from the one most homeowners are asking.
Quick answer
A shop price is for the battery alone, charged at the standard rate of VAT because nothing is installed. An installed price, the kind DESNZ records, covers the battery, fitting it and connecting it to the supply, and is zero-rated until 31 March 2027 when installed in a home. Siting works, protection, the network notification and certificates also sit in the installed price.
What each price includes
| Shop price (supply only) | Installed price | |
|---|---|---|
| The battery | Yes | Yes |
| Fitting and connection to the supply | No | Yes |
| VAT | Standard rate (HMRC Notice 708/6 s2.3) | 0% in a home until 31 March 2027, then 5% |
| Location work under PAS 63100 | No | Where needed, often a separate line |
| Network notification (G98) or application (G99) | No | Handled by the installer |
| Electrical certificate under BS 7671 | No | Yes |
| MCS registration | No | If the installer registers it |
The VAT row alone explains part of the gap. HMRC zero-rates the installation of a battery in a home until 31 March 2027, but section 2.3 of its notice is explicit that energy-saving materials supplied without installation are standard-rated. A box bought online and a battery fitted by an installer are taxed differently even if the hardware is identical.
Why "buy the box, pay someone to fit it" rarely adds up the way it looks
It is tempting to take a shop price, add a labour figure and compare the sum with an installed quote. Several things get lost on the way:
- The VAT treatment. The box carries the standard rate; the relief applies to energy-saving materials supplied and installed together, so splitting the job can cost you the relief on the battery.
- The rules still apply. PAS 63100's location rules, the network notification and the Wiring Regulations don't change because you bought the battery yourself. Someone still has to meet them, certify the work and notify the operator.
- Warranty and responsibility. When the supplier and the fitter are different firms, it can be harder to establish who is responsible if something goes wrong. Ask both before you buy.
- Export payments. GOV.UK's guidance on the SEG expects an MCS (or equivalent) installation and installer before exports are paid for. If that matters to you, check with your supplier before connecting a battery that hasn't been fitted that way.
None of this makes a supply-only purchase wrong, but it means a shop price is not a cheaper version of an installed price. It is a different product.
What a fitted battery comes with that a box doesn't
The difference shows most at handover. A battery installed under the current rules should come with an electrical installation certificate under BS 7671, a statement of conformity with PAS 63100 attached to it, and user instructions that cover shutting the system down and what to do in a battery fire. The network operator will have been notified, or the G99 application approved before the work. If the installer registers the battery with MCS, you also get an MCS certificate, which matters for export payments. A box from a shop arrives with the manufacturer's manual and nothing else.
Questions to ask a retailer
- Is the price for the battery alone, and does it include VAT at the standard rate?
- Is an inverter included, or does the battery need one bought separately?
- Does the warranty require installation by a certified installer to stay valid?
- Who handles a warranty claim if the installer and the seller are different firms?
Second-hand and refurbished batteries
Used batteries sometimes appear for sale at a fraction of a new one's price. PAS 63100, the fire-protection specification for home batteries, excludes second-life batteries from its scope, so an installer working to it may decline to fit one, and DESNZ's figures don't describe what such an installation would cost. If a low price depends on a used or refurbished battery, ask what standard the installation will be certified against and what warranty, if any, comes with the cells.
Portable power stations and plug-in batteries
Some of the batteries sold online are portable power stations: self-contained units with sockets on the front that you charge and plug appliances into. They are not wired into your home's electrics, they are not what DESNZ's statistics count, and they don't need a network notification in the same way. They are useful for some jobs, but their prices tell you nothing about the cost of a home battery system, and the other way round.
Comparing like with like
If you are pricing a battery that will be wired into your home and work with your panels or tariff, use installed prices: DESNZ's medians of £1,300, £890 and £630 per nominal kWh for 2025/26, by size band, are the benchmark. The calculator turns any size into a modelled installed price, and the quote checker compares a real quote with the median. For what drives an installed price above or below that figure, read what adds to a battery quote; for the tax detail, VAT on home batteries.
Sources (page last reviewed 3 November 2026)
- HMRC: VAT on energy-saving materials and heating equipment (Notice 708/6), sections 2.1, 2.3 and 2.19, checked 3 November 2026.
- DESNZ: MCS certified domestic battery installation statistics (April 2024 to March 2026 workbook, published 28 May 2026), checked 3 November 2026.
- BSI / DESNZ: PAS 63100:2024, battery energy storage systems in dwellings (PDF), checked 3 November 2026.
- MCS: notifying distribution network operators (G98 and G99), checked 3 November 2026.
- GOV.UK: Smart Export Guarantee, checked 3 November 2026.
- IET: Amendment 4 (2026) to BS 7671:2018 published 15 April 2026, checked 3 November 2026.
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