James Elston
Published May 22, 2025
Last Updated on May 22, 2025
Types Of Solar Batteries
Investing in solar energy is a smart move, but to truly maximise the benefits, it’s essential to understand the types of solar batteries available.
Whether you’re a UK homeowner, landlord, or managing a commercial property, choosing the right battery storage solution can drastically improve your energy efficiency, reduce grid reliance, and lower long-term energy costs.
In this in-depth guide, we’ll break down the different battery options on the market, compare features like cost, capacity, and lifespan, and help you identify the best fit for your specific needs.
Contents
Types of Solar Batteries – A Quick Overview
Below is a side-by-side comparison of the main types of solar batteries available in the UK to help you make an informed choice:
| Battery Type | Typical Storage Capacity | Average Cost (Installed) | Lifespan | Best For |
|---|---|---|---|---|
| Lithium-Ion | 4–15 kWh | £4,000 – £8,000 | 10–15 years / 6,000 cycles | Homeowners, modern retrofits, smart energy management systems |
| Lead-Acid (AGM/Gel) | 2–10 kWh | £2,000 – £5,000 | 5–10 years / 1,200–2,000 cycles | Budget-conscious users, off-grid cabins, small-scale systems |
| Flow Batteries | 10–30+ kWh | £8,000 – £20,000+ | 20+ years / 10,000+ cycles | Commercial buildings, large homes, long-term storage |
| Saltwater Batteries | 4–10 kWh | £3,500 – £6,500 | 10–15 years / ~3,000 cycles | Eco-conscious users, households avoiding heavy metals |
Different Types of Solar Batteries: An In-Depth Guide
1. Lithium-Ion Batteries
Lithium-ion batteries are the most popular and widely adopted solar battery technology in the UK today. Their high energy density, long lifespan, and minimal maintenance needs make them ideal for domestic solar energy systems.
These batteries are particularly well-suited for homeowners looking for solar batteries that work during a power outage, thanks to their reliability and compatibility with backup systems.
| Pros |
| Cons |
2. Lead-Acid Batteries
The oldest type in the game, lead-acid batteries are a cost-effective but less efficient solution. There are two subtypes: Absorbent Glass Mat (AGM) and Gel batteries. They’re suitable for smaller setups or landlords who need a backup system on a budget rather than daily cycling performance.
| Pros |
| Cons |
3. Flow Batteries
Flow batteries use a liquid electrolyte to store and discharge electricity. These cutting-edge systems are best suited for larger commercial buildings or energy-intensive homes with significant solar capacity.
| Pros |
| Cons |
4. Saltwater Batteries
Saltwater batteries are an emerging green alternative, using non-toxic, non-flammable materials instead of heavy metals or hazardous chemicals. While still gaining traction in the UK, they’re becoming increasingly popular among eco-conscious homeowners who prioritise sustainability and safety in their energy choices.
| Pros |
| Cons |
If you’re wondering if solar batteries are safe for your household or rental property, you’ll be pleased to know that saltwater batteries are one of the safest solar storage options on the market.
Cost Considerations & ROI
The cost of solar batteries depends on type, size, brand, and installation complexity. On average:
- Lithium-ion (7–10kWh): £5,000–£8,000
- Lead-acid (4–6kWh): £2,000–£4,000
- Flow & Saltwater (10kWh+): £8,000–£20,000+
How To Choose the Right Solar Battery for Your Property
Selecting the right battery from the various types of solar batteries isn’t just about picking the most advanced technology, it’s about finding the best match for your property, usage patterns, and budget.
Whether you’re powering a semi-detached home or managing multiple rental flats, here are the key considerations to guide your decision:
Budget
If you’re working within a strict budget, lead-acid batteries offer an affordable entry point. However, it’s worth noting that lithium-ion batteries, while more expensive upfront, typically deliver better value over time due to their longer lifespan and higher efficiency.
Energy Needs
Understanding how much energy your household or building consumes on a daily basis is crucial. The usable storage capacity of a battery must align with your consumption habits.
If you’re wondering where to begin, our guide on what size solar battery I need will help you calculate the optimal setup tailored to your property.
System Compatibility
Not all systems are plug-and-play. Some older solar PV systems may not be compatible with modern batteries without additional components or inverter upgrades. If you already have solar panels installed, it’s important to understand your options.
Learn more about whether you can add a battery to your existing solar system before investing.
Lifespan and Maintenance
Battery longevity and upkeep vary significantly by type. Lithium-ion and flow batteries are generally long-lasting and low-maintenance, making them ideal for homeowners who want a set-it-and-forget-it solution.
If you’re curious about the actual lifespan of different technologies, check out our article on how long solar batteries last. It’s packed with insights to help you plan ahead.
Space Requirements
If space is limited, particularly in smaller UK homes or flats, you may want to avoid bulkier options like flow or lead-acid batteries, which typically require more installation room.
Lithium-ion batteries, in contrast, are compact and more suitable for tighter areas such as utility rooms or garages.
Still on the fence? Our post on are solar batteries worth it weighs up the pros and cons based on cost, space, and usage scenarios.
Ready to Power Your Home Efficiently?
Request Your Free Solar Battery Quote from Eco Happy Today
Choosing the right type of solar battery can be complex, but it doesn’t have to be.
At Eco Happy, our experts will assess your property, your current or planned solar panel system, and your energy usage to recommend the most cost-effective, reliable solar battery solution for your needs.
Fully accredited UK installers
Tailored advice for homeowners, landlords, and commercial buildings
Transparent pricing and long-term support
Request your free solar battery quote from Eco Happy.
James Elston
Boiler Expert
James Elston is the top boiler replacement and heating expert at Eco Happy. He has over 20 years of experience in the industry, focusing on Gas Safe boiler installations and offering home-heating and energy-saving solutions to homeowners across the UK. From sourcing the most energy-efficient combi boiler to providing specialist heating advice, James ensures that Eco Happy maintains the highest standards and best customer service.