- We analysed 27 of the best solar batteries before choosing the top 7
- Factors analysed included value for money, usual capacity, warranty, lifespan, and more
- The best solar battery for capacity is the Tesla Powerwall 2
- The best solar battery for warranty is the Moixa Smart Battery
- A solar battery can save the average three-bedroom household £582 per year
- Check out our full ranking below
Thinking about adding solar batteries to your solar system? That’s great – solar batteries are becoming an essential component in maximising the benefits of solar energy.
As solar battery costs decrease, more homeowners are pairing their solar panels with energy storage solutions.
You can also compare prices for solar-plus-storage with our help. Fill in a few simple details in this short form about your home and our expert installers will get in touch with free quotes.
How did we choose the best solar batteries?
Our team of researchers spent 28 hours analysing seven factors in 27 of the best batteries currently available.
After analysing each battery’s specifications and core attributes, we determined the seven best solar batteries and gave them a rating out of five across each of these key criteria:
- Value for money
- Usable capacity
- Depth of Discharge (DoD)
- Temperature resistance
- Compact size
- Warranty
- Lifespan
- Scalability
Below, you can see our chosen batteries at a glance below, followed by each product in more detail.
The best solar batteries at a glance
Here’s a handy comparison chart with the key specs of our top seven best solar batteries. Before you make your decision, though, check out our complete guide on solar batteries.
| Solar battery model | Typical price | Capacity | Best for |
|---|---|---|---|
| Tesla Powerwall 2 | £5,800-£8,000 | 13.5kWh | Usable capacity |
| Alpha Smile5 ESS 10.1 | £3,958 | 10,000 cycles (full charge to empty = one cycle) | Value for money |
| Moixa Smart Battery | £4,450 | 4.8kWh | Warranty |
| Enphase Encharge 10T | £4,000-£7,000 | 10.5kWh | A range of features |
| Huawei Luna 2000-10 | £5,210.45 | 5kWh-30kWh | Limited space |
| Puredrive PureStorage II | £2,400-£5,500 | 10kWh | Operating temperature |
| Powervault P4 | £4,700-£14,000 | 8kWh-24kWh | Scalability |
Key solar battery criteria explained
Our researchers spent 28 hours investigating the solar battery market, first narrowing the huge field down to the top 27 models currently available. After analysing each one, we then determined the seven best solar batteries.
Here are the key factors that helped us narrow down our selection:
- Value for money – Getting a solar battery isn’t cheap, with even the smallest units costing more than £1,500. However, you can still find some great options that’ll shrink your break-even point below the typical 26.3 years for a solar-plus-storage setup.
- Usable capability – The usable capacity of a storage battery is not how much electricity it can store, but how much of a battery’s total capacity you can actually use. A battery’s capacity can be misleading, as you shouldn’t typically use a battery’s entire capacity, otherwise you run the risk of damaging it. Only a handful of solar batteries have 100% usable capacity — most range between 90% and 95%. When shopping for a solar battery, you should always look out for the battery’s usable capacity and factor that into how much electricity your home needs.
- Depth of discharge – Depth of discharge (DoD) wasn’t part of the seven key factors, but it still deserves a mention. In principle it’s the same thing as a battery’s usable capacity, but the terms are often mentioned together without explanation. Continually using a battery’s full capacity before recharging it will gradually damage it. A battery’s depth of discharge dictates how much of the battery’s capacity should be used before recharging it. For example, if you have a 10 kWh solar battery with an 80% DoD, you should only use it for 8 kWh of energy before allowing it to recharge. Most modern lithium-ion batteries come with a DoD of 90% or more.
- Temperature resistance – It’s important to look at a battery’s operating temperature, as you don’t want to find yourself in either a cold snap or a heat wave and have a battery that stops working. Most solar batteries have an operating range between 0°C and 40°C, but some can keep working comfortably between -20°C and 60°C.
- Compact size – Space can be limited in a home, so make sure you don’t buy a battery and find out you can’t install it where you wanted to. Some manufacturers are better at condensing power into smaller units than others, but this can increase the total cost. This is because smaller batteries with similar power levels to larger units require more complicated cooling mechanisms, to stop them from overheating. Size isn’t everything, however, as some batteries can only be wall mounted – and what might seem small at first, can take up more room than you’d expect because it’s off the floor.
- Warranty – When you’ve installed your solar battery, you’ll want it to last for the longest time possible. Every battery comes with a guaranteed number of ‘cycles’, with one ‘cycle’ being one complete discharge and one complete recharge. Not that you’ll ever use your battery in that way – instead, you’re likely to use about 50% and then charge it back up to 100%, which would count as half a cycle. Every solar battery also comes with a product warranty, which is usually 10 years.
- Lifespan – Another good sign of durability is a battery’s guaranteed number of ‘cycles’ (full discharge and recharge), usually 4,000 or more. With the typical battery likely to go through 250 cycles per year, thousands of cycles add up to many years of good performance.
- Scalability – Most solar batteries are available in a range of capacities, so you can choose according to how much electricity you need to store. The best batteries come as modular units that you can stack to increase (“scale”) their capacity as your needs increase over time, for example if you buy an EV.
- Smart features – A good solar battery is more than just plugging it in and letting it do its thing — you should look for features that get the very best out of it. For example, there are monitoring apps you can install on your phone to see essential metrics, such as remaining charge, whether the battery is charging from the grid or your solar panel setup, and what excess electricity you’re exporting to the grid. Another feature to keep an eye out for is automatic power cut backup, which is where your battery will immediately start powering your home when the grid cuts out.
Tesla Powerwall 2 – best for usable capacity
The Tesla Powerwall 2 has a usable capacity of 13.5 kWh (Tesla)
Tesla is best known for its electric cars – and with that, comes excellent knowledge on making batteries. Its Powerwall 2 is the perfect example, achieving the rare feat of a 100% usable capacity.
That means you can use all 13.5 kilowatt hours (kWh) of the Powerwall 2’s available power, which in situations where you need to use the entire battery’s charge, can be extremely useful.
The majority of solar batteries have usable capacities lower than their actual capacity, so you can only use say, 90% of a battery’s available power.
Powerwall 2 is whisper quiet too – and with sleek aesthetics, it looks every part of the futuristic tech we’ve come to expect from Tesla.
If you need extra power, you can stack multiple Powerwalls together, but with a healthy capacity of 13.5 kWh, most homes should function just fine with a single unit.
Tesla also supplies solar panels, making it easier for homeowners to buy a solar-plus-storage system in one place.
- High capacity
- 100% usable capacity
- Quiet when in operation
- Aesthetic, modern appearance
- Expensive
- Smart features cost extra
Alpha Smile5 ESS 10.1 – best for value for money
The Alpha Smile5 ESS 10.1 costs as little as £3,958 (Alpha)
Solar batteries are rarely cheap, but if you want great value for money then look no further than the Smile5 ESS 10.1 from Alpha. It costs £3,958, which is lower than the typical solar battery price of £4,500, and it has an impressive usable capacity of 9.1 kWh.
That puts the Smile5 ESS 10.1 up there with some of the best mid-to-high range batteries on the market, but without the price hike. For context, the Encharge 10T has a 10 kWh usable capacity, and costs a comparatively eye-watering £8,374.
The lower price tag doesn’t come at the cost of durability either, as the Smile5 ESS 10.1 boasts 10,000 cycles (going from a full charge to empty = one cycle). That’ll mean your battery comfortably lasts well over a decade without much impact to its efficiency.
- Good value for money
- High capacity
- Long lifespan
- 10 year warranty requires internet connection
- Warranty could be nullified if internet cuts out
- Short warranty for the inverter
Moixa Smart Battery (4.8kWh) – best for warranty
the Moixa Smart Battery has a lifetime warranty if registered (Moixa)
Almost all solar batteries come with a 10-year warranty, and the Moixa Smart Battery is no different. What separates it from the pack is the Gridshare initiative, which will give you an unlimited warranty if you join.
Gridshare helps Moixa customers trade excess power stored in its Smart Batteries to the grid. If you join the Gridshare Cashback Scheme, you’ll also get £50 a year for the first three years.
After this, you’ll be entitled to a share in the profits of your electricity exported to the grid, with Moixa paying you 50% for the electricity your Smart Battery generates.
Even though the profits aren’t that high, and you could probably make more with the Smart Export Guarantee, the unlimited warranty is a big bonus.
- Unlimited warranty
- Cashback scheme
- Not very expensive compared to other batteries
- Only has 85% usable capacity
- Low capacity
- Heavy
Enphase Encharge 10T – best for range of features
The Enphase Encharge 10T comes with the Enphase App which includes smart switch and energy optimisation features (Enphase)
The Enphase Encharge 10T is at the cutting-edge of solar batteries, offering a plethora of features that places it firmly on top for impressive technology. The Encharge functions as an all-in-one solution for a home’s entire energy system, meaning it manages more than just solar panels.
It does this with its smart switch feature, which automatically switches between solar, grid, battery, or generator power, depending on what you need.
The Encharge works seamlessly in power outages too, with automatic grid-failure detection, which immediately turns on the battery during power cuts. It’s designed to break connection with the grid immediately in these situations, so there’s no danger of power feeding back into the grid and putting engineers at potential risk.
You’ll also get a beautifully designed app you can use to read how much power you’ve stored, how much electricity you’re currently consuming, and whether you’re using solar power or the grid to charge your battery.
Want to know how solar batteries are installed? Go to our step by step guide.
- Smart switch feature that manages energy use and distribution
- Automatic grid failure detection
- Energy use tracking app
- Lower lifespan that other high-end models
- High cost
- On the heavier side
Huawei Luna 2000-10 – best for limited space
The Huawei Luna 2000-10 weighs 139.6kg (Huawei)
Solar batteries can be bulky, make no mistake, but if space is an issue then the Huawei Luna 2000-10 is a smart choice.
The unit is just 150 mm thick, meaning you can easily install it in a garage with limited space, or even in an under-stair cupboard — and still have room to spare. The Luna 2000-10 is waterproof too, so you can discreetly install it outside, if you prefer.
The battery can be mounted on the wall or installed standing, giving you flexibility for where you want to place it.
We’ve covered the 2000-10 model here, but really, the Luna 2000 is a stackable battery module that comes in 5 kW units — the 2000-10 is the middle-ground option of 10 kW.
You can increase the capacity of a single Luna 2000 tower up to 15 kWh, or connect two complete towers to reach 30 kWh.
- Compact design
- Stackable battery module that allows you to increase or decrease capacity
- High usable capacity
- Can only be used with Huawei inverters
- Shorter lifespan than other batteries of equal cost
Puredrive PureStorage II – best for operating temperature
The Puredrive Purestorage II can operate at temperatures from -20°C to 60°C (Puredrive)
Solar batteries start to work less effectively once they either exceed or fall below certain temperatures, with some models struggling to work efficiently above 30°C.
That’s a temperature the UK has already seen far too often in recent years, as the damaging effects of climate change become more common. And some parts of the home, such as the garage (a popular place to install solar batteries), often become even hotter than the outside world.
PureStorage from Puredrive is the solar battery to go for if you want to future-proof your home storage against significant temperature fluctuations. It can operate efficiently between -20°C and 60°C.
These are temperatures that’ll realistically never be hit in the UK, but it doesn’t hurt to have a guarantee.
- Can operate at very high and very low temperatures
- Not very expensive compared to other batteries
- High capacity for a low price
- Takes up a lot of space
- On the heavier side
Powervault P4 (8kWh) – best for scalability
The Powervault P4 has up to 24 kWh modular units available (Powervault)
Want effortless control over your battery system’s capacity? Get a battery that’s easily scalable — the Powervault P4. You can easily install new battery modules if your power needs increase, and the Powervault P4 can be increased from 8 kWh all the way up to 24 kWh.
With this level of flexibility, you can confidently purchase a futureproof system whilst minimising the risk of oversizing, a common challenge that can impact the ROI of solar battery systems.
The Powervault P4 is also a very smart system – the smartSTOR™ capacity management system makes proactive decisions about whether to prioritise capturing off-peak grid energy or free renewable energy, based on weather forecasts and your live tariff data. This clever technology allows you to save even more money on your energy bills and make use of your battery even when the sun isn’t shining.
- Scalable battery capacity
- Potential for very high capacity
- 100% usable capacity
- High cost
- Heavy
Next steps
The solar battery market is constantly expanding, and more companies are looking to cash in on the increased demand.
With a solar battery and a solar panel system, you’ll typically save £669 on your energy bills. The upfront cost is high, however, putting the technology out of reach of thousands of UK households who would benefit.
If you’re ready to compare prices for solar-plus-storage, we can help. Enter a few details about your home in the form and we’ll put you in touch with our expert installers. They’ll get back to you with bespoke quotes for you to compare.
FAQs
What are the best solar batteries for winter?
Although most batteries will struggle to charge to full capacity using solar power in the winter, the type of battery will make a difference. You should opt for lithium-ion batteries in general, but they’re the best choice for colder climates because they perform better at lower temperatures. Lead-acid batteries are not the optimal choice for winter, because their efficiency can drop to 70% when the mercury plummets. Lithium-ion batteries will still operate at roughly 95% efficiency even when temperatures drop below freezing.
What is the lifespan of a solar battery?
A solar battery will last on average around 12 years, meaning you’ll typically need to purchase two within the lifespan of your solar panel system. Batteries won’t suddenly stop working after this point however, they’ll just gradually become less effective at holding the same level of charge. Think of it like a smartphone battery that’s starting to age — it’ll still power your phone but you’ll definitely notice the battery percentage going down faster than you remember.
Do solar batteries go bad if unused?
Leaving your battery without charge for a long time will start to affect its ability to keep charge. It’ll eventually be unable to hold any charge at all, but this is after many years of not being used so don’t worry about this happening over night. Because of this, it’s typically best to leave your battery charged part way to full.
What reduces a solar battery’s life?
A few factors can reduce a solar battery’s life, including where you store it, the temperatures it’s exposed to, and how you use it.
Solar batteries that are stored outside are exposed to the elements, increasing the risk of damage. In addition, prolonged exposure to temperatures that are outside the operating temperatures indicated on a battery’s manufacturing chart can also affect its longevity.
Lastly, not charging a battery, or keeping it at a full charge for extended periods will, overtime, affect how much of a charge it can hold.
How many solar batteries are needed to power a house in the UK?
Most houses in the UK will only need one solar battery, but the storage capacity of the battery they need will depend on the size of the house.
A typical three-bedroom house in the UK will usually do well with an 8 kilowatt (kW) solar storage battery. Larger houses will need a battery with higher capacity, smaller ones will need a battery with less capacity.
An installer will usually assess the energy usage of the home, and recommend a size of solar battery based on that.
