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Solar battery storage guide 2024

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Solar battery Solar panels plus battery

Yes, without a battery, a solar system connects directly to the grid so you’ll draw electricity from there at night. A solar battery is good as a backup or if you want to be 100% self-sufficient.

A solar battery made from lithium-ion is best. It’s a far more efficient option than other types and works well with the grid.

You can get a 5kW battery for about £5,000 and a 10kW battery for around £16,000. The size you need depends on your daily energy consumption.

As the global community grapples with climate change’s adverse impacts, the shift towards renewable energy sources has become increasingly urgent. Power produced by solar panels has emerged as a key player in transitioning to a cleaner, more sustainable future. However, the intermittent nature of solar energy production presents a challenge. This is where solar battery storage comes into play.

What are solar batteries?

Diagram of a solar panel system with solar batteries included.
Solar batteries store any unused electricity generated by your solar panels to be used later, such as at night when your panels aren’t working (Adobe)

Solar batteries are energy storage devices designed to store the electricity generated by solar panels. These batteries typically use advanced chemistry, such as lithium-ion and lead-acid, to store energy efficiently and reliably. When the best solar panels produce more electricity than is needed for immediate use, the surplus energy is sent to solar panel battery storage. This stored energy can be used when the panels are not producing power, such as at night or on cloudy days. 

Additionally, by storing this excess energy, you can utilise it during peak hours when electricity rates are higher. This reduces the amount of grid-supplied electricity you need to purchase, leading to lower electricity bills. 

While solar panel battery storage systems allow you to consume more solar-generated electricity, you may still produce more energy than you need. You can benefit from the Smart Export Guarantee (SEG) in such cases, as it allows you to sell excess solar-generated electricity back to the grid by offsetting your mains usage or receiving a direct payment. 

Solar batteries are crucial in making solar energy systems more reliable and versatile. They help to mitigate the intermittent nature of solar power production, allowing homeowners to use the energy solar panels produce even when its cloudy

Additionally, solar batteries can provide backup power during grid outages, enhance grid stability, and promote energy independence by reducing reliance on fossil fuels or grid-supplied electricity.

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How to find solar panel battery storage

Finding the right solar batteries for your system involves several steps. It’s important to consider factors such as your energy needs, solar panel costs and budget, and system compatibility when selecting the ideal solution. 

Assess your energy needs

Begin by evaluating your daily energy consumption and patterns. Determine the amount of solar-generated electricity you need to store for use during non-production hours. This will help you identify the appropriate battery capacity and discharge rate required to meet your energy needs.

Choose the right solar battery technology

Solar batteries are available in several types, such as lithium-ion, lead-acid, and flow batteries. Each has advantages and disadvantages regarding performance, cost, lifespan, and maintenance requirements. Research the different battery technologies to determine which best suits your needs and budget. The two most commonly seen types are: 

  • Lithium-ion batteries: These batteries can store a large amount of energy in a relatively small and lightweight package. They also have a longer lifespan than other battery types and have a high energy conversion efficiency – typically around 90–95 per cent. However, lithium-ion batteries are the most expensive option
  • Lead-acid batteries: There are two main types of lead-acid batteries used in solar energy storage. Flooded lead-acid (FLA) batteries require regular topping up with distilled water, while sealed lead-acid (SLA) batteries are maintenance-free but typically have a shorter lifespan. Both types are less efficient than lithium-ion batteries, and their production, recycling, and disposal involve lead, a toxic heavy metal 

Calculate battery capacity and power rating

The capacity of a solar battery is measured in kilowatt-hours (kWh) and indicates the amount of energy it can store. The power rating, measured in kilowatts (kW), determines the electricity the battery can deliver at any given time. To find the right battery storage, consider both the capacity and power rating to ensure the battery can store enough energy and deliver the required power to meet your energy needs.

Determine system compatibility

Ensure the solar battery you choose is compatible with your existing solar panel system, including the inverter and charge controller. Some solar batteries may require specific inverters or additional equipment for seamless integration. Consult your system manufacturer or installer for guidance on compatibility.

Compare costs and warranties

Solar battery costs vary significantly depending on the technology, capacity, and brand. Compare the prices of different batteries and consider installation costs, maintenance requirements, solar panel grants and potential savings on electricity bills. Also, take note of the warranty offered by the manufacturer, which typically covers battery performance and lifespan. A longer warranty period with favourable terms may indicate a high-quality product.

Consult a professional

Solar battery installation involves technical expertise and knowledge of electrical systems. Consult a professional solar panel installer or an electrician with experience in solar battery installations to ensure proper system integration.

John Gilham (1)

Can you use a storage battery without solar panels?, John Gilham, Director at Green Building Renewables

Green Building Renewables is a Yorkshire-based solar and renewable energy company. John told us that many homeowners with roofs unsuitable for solar panels are installing battery-only systems. 


Batteries allow homeowners to make full use of smart tariffs. These tariffs vary electricity prices throughout the day, offering reduced rates during off-peak times – such as late night when demand is low or during periods of high renewable energy production. Batteries can store this cheap electricity for use later when tariffs are higher, saving homeowners money. This is called ‘load shifting’.


John said that although owners of battery-only systems don’t make the big savings that solar system owners do, they still enjoy significantly reduced energy bills with a smaller initial outlay.

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David H icon

Pros and cons of installing solar battery storage, David Hilton, Energy-efficiency and Solar Panels Expert

Once you have fitted solar PV panels to your roof, the next challenge is to make sure you use as much of the energy generated as you can. This then might tempt you to install a solar battery as well. It may seem like a no-brainer – generate energy during the day, use it at night – but the pros and cons of fitting such a product are largely down to the pounds and pence.


Let’s take an average example of a battery capacity of 5kW. You will not have enough energy spare from your solar panels in winter, unless you have a very large array, so we will optimistically assume you can charge the battery 300 days a year and we will also assume that the energy generated is free (you have not allocated the generation against the payback of the solar panels themselves). The cost of peak electricity is around 35p.


Therefore 35p x 5 x 300 days = £525 a year. A decent battery may cost around £3,000 (it may be more or less, depending on what you buy and where you buy it) to install, so you are looking at a minimum of around six-year payback. So, payback might be an advantage or a disadvantage, depending on how the numbers stack up for you.


The demand for batteries is now very high and the raw materials required to make them leave many unanswered environmental questions. This is my biggest concern. So, can a solar battery make financial sense? It certainly looks like it can. Do I want a home battery? Yes. Should I have a home battery? I am not sure.

Which solar panel battery is the most energy efficient?

Project Solar sells a range of solar storage batteries from several manufacturers.

SolaX Triple Power 5.8kWh Battery (TP58)

Solax Triple Power solar battery
SolaX TP58 solar battery (SolaX)

The TP58 is a lithium-ion battery intended for residential solar energy storage applications. It’s equipped with multiple safety features, including overcharge and over-discharge protection, short circuit protection, and thermal management systems, and comes with a 10-year warranty.

The SolaX Triple Power battery series is designed to be scalable, allowing users to connect multiple batteries in parallel to increase the overall energy storage capacity. This flexibility makes it easy to customise the storage system according to specific energy requirements.

Fox ESS Solar Storage Systems

Fox ESS Solar Battery Storage
A Fox ESS solar battery (Fox)

Fox ESS energy storage systems use lithium-ion batteries to store and manage the energy generated by solar panels efficiently. It offers a range of batteries with varying capacities to meet different energy storage needs, allowing users to select one that best fits their requirements.

BSB FAG Series Solar Batteries

BSB FAG series solar batteries
BSB FAG solar battery series (BSB)

BSB Power is a Chinese battery manufacturer that produces a wide range of batteries, including the FAG series of sealed lead-acid solar batteries. BSB Power says its batteries exhibit a low self-discharge rate, ensuring they can retain their charge for an extended period when not in use.

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Do I need storage batteries for solar panels?

Whether you need storage batteries for your solar panels depends on several factors. 

With a grid-tied system, you might not need storage batteries, as you can rely on supplied energy for backup power when your panels are not generating enough.

Solar storage batteries become essential for off-grid systems or areas with unreliable grid connections. They help store excess solar energy during the day, which can then be used during the night or periods of low solar production.

Incorporating a storage battery into your solar system can help you increase energy independence, reduce your carbon footprint and minimise energy bills.

Tom Armstrong, Project Solar

Do you recommend batteries? – Tom Armstrong, Sales Director at Project Solar

Yes, battery technology has changed a lot in recent years, making them a valuable addition to any solar panel system.


Using off-peak grid electricity to charge the solar battery between midnight and 4 am allows households to use that energy during the day and top up with solar-generated power.


The main reason for not adding a battery to a solar system is if the homeowner wants a quick panel installation to increase the value of their home.


Five years ago, only five per cent of homeowners bought batteries. Now, 95 per cent of installations include a battery, mainly due to electricity price rises.

How much does a solar battery cost?

The price you can expect to pay for a solar battery will depend on your energy consumption and the size of battery you will need. We’ve found solar batteries that can cost as little as £1,200, but the price may hike up to £6,000, depending on your energy usage and house size.For example, if you install six solar panels, you’ll need a solar battery system size of 4kWh, which will cost you around £2,800. The average cost sits at around £4,500. 

This is a costly investment to add to the initial price of installing solar panels, so it’s worth doing your own research and getting quotes. But, working alongside solar panels, solar batteries can bring  your energy bills down, as well as reduceing your carbon footprint.

Are there solar panel kits with batteries and inverters?

There are solar panel kits available that include solar panels for homes, batteries, and inverters, along with other essential components such as mounting hardware, charge controllers, and wiring. These kits are designed to provide a complete, all-in-one solution, with the components working together seamlessly.

Purchasing a solar panel kit can be more cost-effective than buying individual parts separately, as manufacturers and suppliers often bundle these components together at a discounted price, so they can be a wise investment if you’re looking for cheap solar panels.

Frequently asked questions about solar battery storage

A solar panel battery bank is a group of batteries connected together to store the electricity generated by solar panels in a solar energy system. The battery bank serves as an energy storage solution that allows you to use solar-generated electricity when the panels are not producing power, such as at night, on cloudy days, or during periods of high energy demand.

A solar panel battery bank typically includes the following components:

  • Batteries: The batteries in a battery bank can be of various types, such as lead-acid, lithium-ion, or flow batteries. The choice of batteries depends on factors like energy storage capacity, budget, and space availability. The batteries are connected in series or parallel – or a combination of both – to achieve the desired voltage and storage capacity
  • Charge controller: A charge controller is essential for managing the flow of electricity between the solar panels, battery bank, and the load, ensuring the batteries are charged efficiently and not overcharged or over-discharged
  • Inverter: An inverter is responsible for converting the direct current (DC) electricity stored in the battery bank into alternating current (AC) electricity, which can be used by household appliances
  • Wiring and connections: Wiring and connections are required to connect the batteries, charge controller, inverter, and solar panels, ensuring electricity flows smoothly and safely throughout the system
  • Monitoring and management system: Some solar panel battery banks include monitoring and management systems that allow you to track the performance of the battery bank, manage energy usage, and troubleshoot any issues

A solar battery charger is a device that uses solar energy to charge batteries. They are typically used for charging mobile phones, car batteries, laptops, and flashlights. Most chargers are portable and, as such, are a convenient, environmentally friendly way of charging your devices.

Compare different solar battery chargers based on their specifications, including charging capacity, output voltage, efficiency, and battery compatibility. Also, consider additional features, such as built-in charge controllers, USB ports, or portable designs.

The lifespan of solar panels battery storage depends on the type of battery, its usage, and how well it is maintained. 

  • Lithium-ion batteries have a longer lifespan than lead-acid batteries, generally lasting 10-15 years or more. They have a higher energy density, better performance in high and low temperatures, and a lower self-discharge rate, contributing to their longer lifespan
  • Flooded lead-acid batteries can last five to10 years, depending on factors like maintenance, temperature, and depth of discharge. These batteries require regular maintenance, such as topping up the electrolyte and checking the water levels
  • Sealed lead-acid batteries, including Absorbent Glass Mat (AGM) and Gel batteries, typically have a lifespan of four to eight years. They are maintenance-free and generally more resistant to temperature fluctuations and deep discharges than flooded lead-acid batteries

To maximise the lifespan of your solar panel batteries, follow these tips:

  • Follow the manufacturer’s guidelines for proper installation, usage, and maintenance
  • Keep the batteries in a well-ventilated, temperature-controlled environment to avoid overheating or freezing
  • Avoid deep discharging the batteries, as it can reduce their lifespan. Use a charge controller to manage the charge and discharge levels
  • Regularly monitor the battery’s performance and health to detect any issues early and address them promptly.

It’s essential to consider the expected lifespan of the solar panel batteries when designing your solar energy system and to plan for their eventual replacement to ensure continuous power supply and optimal system performance.

Katharine Allison

Energy Saving Writer

As Independent Advisor’s energy saving expert, Katharine, a keen advocate for sustainability, is an authority on solar panels, double glazing, and cutting-edge renewable energy technologies. Her dedication merges with a commitment to enlighten and steer readers toward embracing eco-friendly solutions and the latest trends in sustainability.

With over 10 years of experience, she has worked with some of the UK’s leading companies and publications, including the Federation of Master Builders, Architectural Digest, and Denon Construction. 

Katharine is particularly passionate about consumer causes and animal welfare and has art, philosophy, and psychology degrees. She lives with her sled dogs in East Sussex.

david hilton

David Hilton

Energy and Renewables Expert

David Hilton is a Director at Heat and Energy Ltd, and an expert in conventional and sustainable building, energy efficiency services, and healthy homes. In his role at Heat and Energy, David supports projects from design brief to completion with technical, sustainability and strategic advice. He also advises on building fabric and heating, including conventional, modern and alternative systems.

As an expert in energy efficiency and sustainable building, David has a masters degree in sustainable architecture and is a regular contributor to Homebuilding & Renovating, Selfbuild and Design, Grand Designs, and Build It magazines, The Metro and The Independent newspapers as well as various trade magazines.

David is also a member of professional bodies and organisations including Gassafe and the Gloucester Design Review Panel.

David is a frequent speaker on heating, renewables and modern building methods at the Homebuilding and Renovating shows as well as training installers of heat pumps, photovoltaics, and solar thermal systems. In addition, he delivers courses and seminars at the National Self Build and Renovation Centre.