Russell Andrews
A home battery stores spare daytime solar so you can use it in the evening. How much that helps depends on your usage, your tariff and your design, and savings are not guaranteed. This guide to the best solar batteries UK homeowners compare in 2026 covers the batteries most often considered, what each one does well, and the questions that decide which one fits your house.
Before you compare brands, it helps to know how much storage you actually need. Our home battery size guide explains capacity, power and usable storage in plain terms.
By Russell Andrews
Tesla Powerwall 3: 13.5 kWh of usable storage, with backup options
Tesla's UK datasheet lists 13.5 kWh of usable energy for the Powerwall 3, with a continuous output of up to 11.04 kW depending on local conditions. Extra Powerwall 3 Expansion units can add further capacity. For backup in a power cut, Tesla says a separate Backup Gateway is needed, so check that it is included in any quote. Heatable's buying guide puts installed pricing for the Powerwall 3 at the premium end of the market, which suits households with high evening use or an electric vehicle.
Duracell Dura5: a mid-range choice
The Dura5 uses LiFePO4 (lithium iron phosphate) chemistry, which is chosen for safety and long life, and it comes with a 10-year warranty. Its 5 kWh units suit households with more modest evening use, and they can be combined for more storage.
Growatt: several battery ranges
Growatt offers several battery ranges. Compare the exact model's usable capacity, compatible inverter and permitted expansion arrangements. Module sizes and installation requirements differ across the range.
Other established names
SonnenBatterie is a long-standing brand in the UK market. Ranges change over time, so if you want to compare beyond the batteries above, ask your installer which models are currently available and supported, and how long the manufacturer commits to supplying spares.
Adding a battery to panels you already have
Many homes add a battery later. Whether that is simple depends on your existing inverter and how it is connected. Some setups need only the battery and a small amount of extra equipment, while others need the inverter changed too. An installer should check this before quoting, and our home battery storage page explains the options. If you have no solar panels at all, a battery can still be charged from the grid on a cheaper tariff, as covered in our guide to tariffs and batteries.
Warranty and lifespan
Energy Saving Trust points out that batteries generally have a shorter life than solar panels, so the warranty matters more than it does for panels. Compare the number of years, what the warranty says about how much capacity must remain, and whether labour is covered. Ask who you would contact, and whether that company is likely to still be supporting the product in ten years.
Safety and installation standards
A battery is a large piece of electrical equipment, so where it goes matters. Ask where the unit will be fitted, how it is isolated and protected, and whether the installer is MCS certified. Our MCS certification page explains what that standard covers, and the HIES protection scheme page explains what protection sits behind the installation itself.
What decides the right choice for your home
FactorWhy it mattersEvening and overnight useSets how much stored energy you will use each dayPower cut backupEnergy Saving Trust notes a battery does not normally power your home in an outage unless extra equipment is included, so decide whether you want itAvailable spaceCompact modular options suit smaller utility rooms or garagesInverter compatibilitySome pairings are more efficient together (DC-coupled) than others (AC-coupled)WarrantyCheck the length, what it says about capacity over time, and who honours it
Be realistic about what a battery saves
A battery's value depends on how much surplus solar you have to store and how much of your usage happens in the evening. A battery added to a small solar system, or to a household that already uses most of its electricity during the day, will do less than one matched to your pattern. Ask for a quote that shows the assumptions behind any figures, so you can judge them yourself. Our guide to what to look for in a solar and battery quote shows what to check.
Next step
If you would like a battery designed around your actual usage, request a free quote. If you already hold a quote from another installer, send it in and REST will review it, subject to assessment and approval.