The best solar batteries explained
Comparing the leading solar batteries, including the Powerwall 3.
Battery storage is a smart addition to any home. But choosing the best solar battery isn’t always as simple as picking the biggest brand or the largest capacity. So: which solar battery is best for your home?
In this guide, we explain how the leading solar batteries compare, what sets them apart, and which one might suit your home best.
The best solar batteries in the UK
The batteries featured below are some of the best options available in the UK market. They are all known for being high quality, efficient, and backed by long-term warranties. They all follow industry safety standards such as PAS 63100, have a fully traceable and ethical supply chains, and put data in your hands with a user-friendly portal. They also have the ability to be paired with additional units or modules over time, allowing households to increase their storage capacity as their energy needs grow.
Tesla Powerwall 3
Capacity: 13.5 kWh
Power output: Up to 11.04 kW
Inverter: Integrated solar inverter with 97.5% efficiency
Scalability: Up to 4 units can be connected together
Warranty: 10 years
Best suited to homeowners that want a simple, all-in-one battery with minimal extra equipment.
When Tesla launched the original Powerwall in 2015, it quickly attracted attention thanks to the company’s global reputation in electric vehicles – becoming one of the first companies to successfully bring battery storage into the mainstream. The latest version, Powerwall 3, builds on that reputation by combining several components that are often separate in other systems into a single unit.
Most notably, it includes an integrated solar inverter, meaning solar panels can connect directly to the battery without needing additional hardware. This simplifies installation, reduces system complexity, and can improve efficiency by reducing the number of energy conversions required between solar panels, the battery and the home.
Another reason the Powerwall 3 stands out is how well the system is designed to work as a complete energy ecosystem rather than just a standalone battery. Through the Tesla app, homeowners can monitor energy generation, battery storage, and home usage in real time, while features like time-based control help optimise when the battery charges or discharges based on electricity prices.
Tesla has also focused heavily on software and user experience, with regular software updates that improve system performance over time. Combined with its high power output, strong backup capabilities and the ability to integrate with Tesla electric vehicles, the Powerwall 3 has become one of the most recognisable and widely discussed home batteries available today.
SigEnergy SigenStor
Capacity: 6kWh or 9kWh per battery module
Power output: Up to 12 kW (system dependent)
Inverter: Integrated hybrid inverter (up to ~98% efficiency)
Scalability: Up to 6 modules can be connected together
Depth of discharge: Up to 100% usable capacity
Warranty: Typically around 10 years
Best suited to homeowners who want a flexible, modular battery system that can expand over time as their energy needs grow.
The SigEnergy SigenStor stands out because it’s designed more like a complete home energy platform than a standalone battery. Instead of installing separate pieces of equipment around the home, the system can stack multiple components together in one tower-style unit, including the battery modules, inverter and optional EV charger. This approach helps reduce wall clutter and can simplify system design compared with setups that require several separate devices.
Another key difference is how expandable the system is. SigenStor is built around interchangeable modules that can be added or upgraded over time, making it particularly suited to homes planning to electrify more of their energy use in the future. For example, homeowners might start with battery storage and solar, then later add EV charging or increase battery capacity as their needs grow. This modular “energy stack” approach is one of the reasons the SigenStor is often described as one of the most flexible residential energy systems currently available.
SolarEdge Home Battery
Capacity: 10 kWh per battery module
Power output: Depends on the paired SolarEdge inverter
Inverter: Requires SolarEdge Home Wave or Hub inverter (DC-coupled system)
Scalability: Up to 3 modules can be connected per inverter
Depth of discharge: Up to 97% usable capacity
Warranty: 10 years
Best suited to homes that already have a SolarEdge solar system and want a battery designed to work seamlessly within that setup.
The SolarEdge Home Battery is designed specifically to work as part of the wider SolarEdge ecosystem rather than as a standalone battery. It connects directly with SolarEdge inverters and monitoring software, meaning the solar panels, inverter and battery are all managed through the same system. This tight integration allows the battery to store excess solar energy efficiently and automatically prioritise powering the home when electricity prices are higher or when solar generation drops.
Another key difference is SolarEdge’s DC-coupled system design, which allows energy from solar panels to flow directly into the battery without multiple conversion steps. This helps reduce energy losses and maximise how much of the solar power generated can actually be stored and used later. The battery is also built to scale within SolarEdge systems, with up to three units connected to a single inverter to increase storage capacity if needed.
The best home batteries compared
| Feature | Tesla Powerwall 3 | SigEnergy SigenStor | SolarEdge Home Battery |
| Price range | £6,700 – £7,600 | £4000 – £7000 | £5,000 – £6,000 |
| Capacity (how much energy the battery can store) | Up to 13.5 kWh per unit | Up to 9kWh per module | Up to 10 kWh per module |
| Output (maximum power the battery can deliver at once) | Up to 11.04 kW per unit | Up to 4.6 kW per module | Up to 5.0 kW per module |
| Depth of Discharge (how much of the stored energy you can use) | Up to 100% | Up to 100% | Up to 97% |
| Efficiency (how much of the energy used to charge the battery is available when it’s discharged) | Up to 97% | Up to 98% | Up to 94.5% |
| Scalability (how many battery units or modules can be combined together) | Up to 4 units | Up to 6 modules | Up to 5 modules |
| Warranty (manufacturer guarantee for performance and lifespan) | 10 years | 10 years | 10 years |
| Backup capability (ability to power your home during a power cut) | ✔ | ✔ (add-on required) | ✔ (add-on required) |
| Time-of-use optimisation (ability to automatically charge when energy is cheaper and discharges when it’s more expensive) | ✔ | ✔ | ✔ |
| EV charging integration (ability to prioritise charging your electric vehicle) | ✔ | ✔ | ✔ (add-on required) |
| Load control (ability to prioritise or manage household energy use) | ✔ | ✔ | ✔ (add-on required) |
| Forecasting (ability to use data like weather, energy prices, and home usage patterns to plan battery usage) | ✔ | ✔ | ✔ |
| Integrated solar inverter (solar inverter built into the battery system) | ✔ | ✔ | ✔ (add-on required) |
| App rating (Apple App Store) | 4.4 ★ | 3.6 ★ | 4.6 ★ |
| Compatibility | Flexible for new or existing solar installs | Designed for hybrid solar setups | Designed for SolarEdge ecosystem only |
By understanding the differences between the leading options, you can choose a system that not only stores your solar power effectively today, but also supports how your home’s energy use may evolve in the future.
If you’re considering adding battery storage to your home, it’s always worth speaking with an expert who can help design a system around your household’s energy needs, solar setup and electricity tariff.
Yes. They allow you to store excess solar power for use later in the day, reducing how much electricity you need to buy from the grid. They can also help you take advantage of smart off-peak tariffs and, in some cases, provide backup power during a power cut.
Read more: Are solar batteries worth it? | Good Energy
Cheaper batteries often come with shorter warranties, lower efficiency, and less reliable performance over time. Compared to more premium models, the Tesla Powerwall 3 price may be higher – but they’re designed to last longer, integrate more smoothly with solar systems, and include advanced energy management features that significantly improve long-term value.
The Tesla Powerwall 3 combines high power output, large storage capacity and an integrated solar inverter in a single unit. It’s also known for its simple installation, strong backup capability and easy energy monitoring through the Tesla app.
In the UK, a Tesla Powerwall 3 typically costs around £6,700 – £7,600 per battery unit depending on installation requirements.
Other highly rated home batteries include the SigEnergy SigenStor and the SolarEdge Home Battery. These systems offer strong performance, modular expansion options and smart energy management features, making them popular alternatives depending on your solar setup.
Yes. Solar batteries can be installed without solar panels and charged from the grid, often using cheaper off-peak electricity tariffs. This allows households to store low-cost energy and use it later when electricity prices are higher.
