Sigenergy is one of the most searched home battery brands in the UK right now, and almost all of that interest is about one product: the SigenStor. We design and install Sigenergy systems across Dorset, Hampshire and Wiltshire, so this guide sets out what the SigenStor actually is, how the battery sizes work, and who it suits, in plain English.
What is the Sigenergy SigenStor?
SigenStor is what Sigenergy calls a 5 in 1 home energy system. Instead of a separate inverter on the wall and a battery in the corner, it puts five jobs into one modular stack:
- a hybrid solar inverter (the Sigen Energy Controller)
- battery storage (Sigen Battery modules)
- an energy management system
- battery power conversion, with a DC optimiser in each battery
- an optional DC EV charging module
The Energy Controller sits on top, the battery modules stack underneath, and the whole thing looks like one tidy tower. It comes in single phase and three phase versions, which is less common in the home battery market than you might expect.
Sigenergy battery sizes
The Sigenergy battery is sold in modules rather than one fixed box. Sigenergy’s datasheet gives these figures for the two core modules:
| Module | Nominal capacity | Usable capacity | Max charge and discharge |
|---|---|---|---|
| Sigen Battery 5.0 | 5.38 kWh | 5.2 kWh | 2.5 kW |
| Sigen Battery 8.0 | 8.06 kWh | 7.8 kWh | 4 kW |
Each Energy Controller takes between one and six modules. So a SigenStor can be a single module for modest evening use, or a much larger stack for a home with an EV, a heat pump and high overnight demand. Two 8 kWh modules give roughly 15.6 kWh usable, which is a popular size for a typical family home with solar.
Two things to know about the power figures. First, the charge and discharge rate goes up as you add modules, so a bigger stack can also deliver more power at once. Second, the Energy Controller has its own rating, and the system can only deliver what the controller allows. We size both together.
Can you add more Sigenergy batteries later?
Yes, and this is one of the strongest arguments for SigenStor. Because each module has its own DC optimiser, Sigenergy designs the system so newer modules can be added to an older stack without the whole battery being held back by the oldest one. In practice that means you can start with what you need today and add capacity when you buy an EV or fit a heat pump.
The limit is six modules per controller. If you think you will need a large battery within a few years, tell us at survey and we will plan the space and the controller size for it.
Battery chemistry and safety
Sigen batteries use lithium iron phosphate (LiFePO4) cells, the chemistry most of the home battery market has moved to because of its thermal stability and long cycle life. Sigenergy also builds in cell temperature monitoring, insulating barriers and an internal fire suppression system. The modules are IP66 rated and specified to run between minus 20 and 55 degrees C, with built-in heating for cold weather, so they can go outside within Sigenergy’s installation rules. Most of our customers still prefer a garage or utility room where possible.
Solar and the Energy Controller
The Energy Controller is a hybrid inverter, so your solar panels connect straight into it. Single phase controllers have two MPPTs (independent solar inputs), and selected three phase controllers have up to four. That matters on roofs with panels on two or three faces, because each face can be tracked separately. If you already have solar, the controller can often replace your old inverter and run your existing panels plus the new battery.
Backup in a power cut
A SigenStor on its own does not automatically keep your lights on in a power cut. For backup you need a Sigen Gateway. With the HomePro SP-F single phase gateway, Sigenergy specifies 0 ms load-side disruption when it is used with a Sigen Energy Controller and battery, which means supported circuits keep running without a flicker. How much of the house you can run still depends on the controller rating, the battery size and how we wire the backup. Our Sigenergy Gateway guide goes into the detail.
The mySigen app
Everything is monitored and controlled in the mySigen app: live solar, battery, home and grid flows, energy history and costs. Sigen AI Mode can plan charging and discharging around your tariff, the weather and your solar forecast. That is useful on time of use and dynamic tariffs, where manually setting charge windows quickly gets tedious.
Sigenergy warranty
Sigenergy gives the Sigen Battery and Energy Controller a 10 year product warranty in Europe. The battery performance guarantee is 70 percent usable energy after 10 years or a minimum warranted throughput, whichever comes first (15.85 MWh for the 5 kWh module and 23.77 MWh for the 8 kWh module). The optional DC EV module has a shorter warranty. On top of the manufacturer warranty, every DES installation carries our own workmanship warranty and an IWA insurance-backed guarantee.
For context, Tesla’s UK Powerwall 3 warranty guarantees 80 percent capacity at 10 years, so Sigenergy’s retention figure is not the strongest in the market. It is still a solid, mainstream warranty.
Who the SigenStor suits
- Homes that want to start small and add battery capacity later
- Three phase properties and homes with complicated roofs
- Households on smart or dynamic tariffs
- People who want proper backup with a gateway
- EV households, now or in the near future
It is less of a slam dunk for a simple single phase home that just wants a standard sized battery. In that case a GoodWe ESA stack or a Tesla Powerwall 3 can be just as good a fit. We compare them honestly in Sigenergy vs GoodWe and Sigenergy vs Tesla Powerwall 3.
The one honest caveat
Sigenergy is a young company, founded in 2022. The hardware is impressive and the reviews are strong, but there is not yet a decade of UK field data behind it. That is not a reason to avoid it. It is a reason to buy it from an installer who will be around to support it, which is exactly why we only fit with our own employed teams.
Talk to a local Sigenergy installer
If you are weighing up a Sigenergy battery, we will survey your home, size the controller, battery and backup properly, and give you a fixed written quote. See our Sigenergy installer page, or request a free quote for Dorset, Hampshire and Wiltshire. You can also call us on 01202 985 888.