| Typical battery range (Energy Saving Trust, page updated 19 August 2026) | £1,500 to £10,000; about £4,600 for a 5kWh system |
|---|---|
| Typical battery range (MoneySavingExpert) | £1,500 to £10,000; around £5,000 for a standard 5kWh system |
| Usable share of stated capacity (MoneySavingExpert) | 85% to 95% (most modern batteries) |
| VAT on battery installation (HMRC, VAT Notice 708/6) | 0% from 1 February 2024 to 31 March 2027 |
What batteries cost
There is no official cost dataset for home batteries. The government’s solar cost data leaves batteries out. Therefore we have to lean on consumer sources, and the evidence is thinner than it is for panels.
Energy Saving Trust says battery storage can range from £1,500 to £10,000. It puts a 5kWh system at around £4,600. Its page was last updated on 19 August 2026.
MoneySavingExpert gives the same range. It says a standard 5kWh system averages around £5,000. Which? lists some products without installation, for example a Powervault 3 at £3,229 for 4kWh and £4,999 for 8kWh, both excluding VAT.
Prices vary by brand, size and installer, so get written quotes. However, the panel side of the bill has better data, so see our guide to solar panel costs.
Work out the price per usable kWh
A quote may show only a total price and a headline size. Yet a price per kWh lets you compare two batteries fairly.
First, divide the battery price by its stated capacity. Then repeat the sum using usable capacity. MoneySavingExpert says usable capacity is typically 85% to 95% of the total, so an 8kWh battery gives 6.8 to 7.6kWh.
Here is the arithmetic on both sources. These are our own sums, not published prices.
| Source and price | Per stated kWh | Per usable kWh (at 95% to 85%) |
|---|---|---|
| Energy Saving Trust, 5kWh for £4,600 | £920 | £968.42 to £1,082.35 |
| MoneySavingExpert, 5kWh for £5,000 | £1,000 | £1,052.63 to £1,176.47 |
Neither source says whether its 5kWh figure is stated or usable capacity, so treat the two columns as a range. Remember that these are consumer-site figures, not a price list.
Usable versus nominal capacity
Which? explains that usable capacity is usually less than stated capacity. Batteries lose some energy when they charge and discharge. Most are also not built to empty fully on a regular basis, because that would shorten their life.
Energy Saving Trust adds that a system stops drawing from the battery at a set level, maybe 20% of total capacity. Therefore ask every installer for the usable figure in writing.
The MCS standard points the same way. Its performance estimate template for a system with storage includes a line for the assumed usable capacity of the storage device. A quote may show only a headline kWh, so ask for that line.
AC or DC coupling
Coupling means how the battery links to your panels.
- DC coupled. Which? says these connect directly to the generation source and need no additional inverter. MoneySavingExpert says they suit new installs.
- AC coupled. Which? says these connect after the generation meter and need an AC/DC power unit. MoneySavingExpert says they are what you need to add a battery to an existing system.
So the right type depends on your situation. If you already have panels, read our guide to adding a battery to existing solar panels. Check that the quote names the extra inverter if it is AC coupled.
Warranty and lifespan
Which? says battery systems often come with a 10-year warranty. Energy Saving Trust gives a typical lifespan of about 10 to 12 years. MoneySavingExpert quotes 12 to 15 years.
Panels can last 25 years or more, so Which? advises you to plan for replacing the battery at least once. Warranty terms differ between products, so ask the installer to put these points in writing:
- the warranty length in years;
- how much capacity the battery must keep by the end;
- any limit on total energy or cycles;
- who honours the warranty if the installer stops trading.
VAT on batteries
HMRC applies a zero rate to batteries installed in a home from 1 February 2024 until 31 March 2027. This covers three cases. A battery fitted with new panels is normally part of one zero-rated supply. A battery added to existing panels qualifies. A standalone battery that stores grid electricity also qualifies.
HMRC says installations of energy-saving materials revert to the 5% reduced rate from 1 April 2027. Since timing matters, ask your installer which rate applies on your installation date. Our guide to grants and VAT covers the rules in more detail.
Help with the cost
Energy Saving Trust says there are no dedicated solar panel grants from the UK Government, although the Warm Homes: Local Grant can cover a battery for some low-income homes in England. DESNZ guidance says the battery must go with solar panels, old or new. Councils run the scheme.
Is the battery worth it?
That depends on how you use electricity, not only on the price. Our article asks whether a solar battery is worth it. Energy Saving Trust says savings can be significant, but may not justify the cost alone.
A bigger array changes the sums too, because more panels mean more spare electricity to store. See how many solar panels you need before you size a battery. Also check whether scaffolding is already counted in the panel price, so you do not pay for it twice.
Check your battery quote
Use this list on any battery line.
- Is the capacity stated or usable?
- What is the price per usable kWh?
- Is it AC or DC coupled, and is any extra inverter priced?
- What does the warranty cover, and for how long?
- Is VAT shown at 0%?
Then run the whole quote through our free quote checker. You can also see what South West installers charge and how Welsh quotes compare.