Sigenergy might not be the first brand that comes to mind when you think of home batteries, but it's a name we've been installing more frequently over the past year. For homeowners looking for capable battery storage without the Tesla price tag, Sigenergy offers an interesting middle ground. Here's our honest assessment.
What Is Sigenergy?
Sigenergy is a manufacturer that produces lithium iron phosphate (LFP) battery storage systems under the SigenStor brand. They've been making waves in the UK market by offering solid specifications at competitive prices, all while maintaining MCS certification.
Their product range includes:
- SigenStor Battery Modules — Available in 6 kWh and 9 kWh sizes, stackable up to 6 modules (54 kWh max)
- SigenStack — 12 kWh modules for larger installations
- Energy Controllers (Hybrid Inverters) — Single-phase (3.6 kW, 5 kW, 6 kW, 8 kW, 10 kW, 12 kW) and three-phase (10 kW, 12 kW, 15 kW, 17 kW, 20 kW, 25 kW, 30 kW)
Sigenergy SigenStor Specifications
Here are the key specs for the Sigenergy SigenStor battery system:
| Specification | Value |
|---|---|
| Battery Module Sizes | 6 kWh and 9 kWh (plus 12 kWh SigenStack) |
| Max Modules Per Controller | 6 modules (up to 54 kWh) |
| Depth of Discharge | 100% |
| Round-Trip Efficiency | ~95% |
| Warranty | 10 years / 70% capacity guarantee |
| Cell Chemistry | Lithium Iron Phosphate (LFP) |
| Operating Temperature | -20°C to 60°C |
| IP Rating | IP66 (outdoor capable) |
| Inverter Efficiency | Up to 97.7% |
What We Like About Sigenergy
Excellent Capacity-to-Price Ratio
Sigenergy's standout feature is value. An 18 kWh system (2 × 9 kWh modules) typically costs £6,000–£7,500 installed — that's competitive with Fox ESS and significantly cheaper than premium brands like Tesla or Anker. For homeowners who want meaningful battery capacity without breaking the bank, Sigenergy delivers.
Flexible Module Sizes
With both 6 kWh and 9 kWh modules available, you can configure systems in various sizes: 12 kWh, 18 kWh, 24 kWh, 27 kWh, 36 kWh, 45 kWh, or 54 kWh. This flexibility means you can match the system precisely to your needs and budget.
Impressive Scalability
With support for up to 6 modules per controller (54 kWh) — and multiple controllers allowing even more — Sigenergy can handle everything from modest home installs to commercial applications. This flexibility is unusual at this price point.
100% Depth of Discharge
Unlike some competitors that only allow 90-95% depth of discharge, Sigenergy lets you use 100% of the rated capacity. A 9 kWh module gives you the full 9 kWh usable.
Full Inverter Range
Sigenergy offers both single-phase inverters (3.6 kW to 12 kW) and three-phase inverters (10 kW to 30 kW). This makes them suitable for everything from standard UK homes to large properties and small commercial installations.
MCS Certified
All Sigenergy products we install meet MCS certification requirements. This means you can access the Smart Export Guarantee (SEG) and stay eligible for any future government schemes. We don't compromise on this.
Outdoor Installation
With an IP66 rating, SigenStor batteries can be installed outdoors without additional enclosures. This provides more flexibility for homes with limited indoor space.
Where Sigenergy Could Improve
Brand Recognition
Let's be honest: when customers research battery brands, they find plenty about Tesla and Anker. Sigenergy has less online presence and fewer independent reviews. This can make the decision feel riskier, even though the products themselves perform well.
Support Infrastructure
As a newer entrant to the UK market, Sigenergy's support infrastructure is still developing. If something goes wrong, resolution times can be longer than with brands that have been established in the UK for many years.
App Experience
The Sigenergy monitoring app (mySigen) is functional but basic. It does the job — showing generation, consumption, battery state — but it lacks the polish of Anker's app. If you're a data enthusiast who wants detailed analytics, you might find it limiting.
Aesthetics
Sigenergy batteries are industrial-looking. They're designed to go in garages and plant rooms, not living spaces. The casing is functional rather than decorative. If aesthetics matter, consider Anker or Tesla instead.
Who Is Sigenergy Best For?
Based on our experience installing Sigenergy systems across East Sussex, here's who we'd recommend it to:
- Value-focused buyers — If you want maximum kWh per pound spent, Sigenergy is hard to beat
- Larger capacity needs — The 6 kWh and 9 kWh modules and high scalability suit 15 kWh+ installations
- Outdoor installations — The IP66 rating means no need for additional enclosures
- Three-phase properties — The comprehensive three-phase inverter range (10-30 kW) suits larger homes
- Practical homeowners — Who care more about performance than brand prestige
- Commercial applications — The scalability and pricing work well for small business installs
Who Might Prefer Something Else?
- Brand-conscious buyers — If you want a name your neighbours recognise, consider Tesla
- Aesthetics priority — Anker Solix X1 is the clear winner for visible installations
- Those wanting established UK support — Some brands have been in the UK market longer with more developed support networks
- Tech enthusiasts — The app experience is basic compared to competitors
Real-World Performance in East Sussex
Here's what we've observed from our Sigenergy installations:
- Efficiency: 93-95% round-trip efficiency — in line with specs
- Winter performance: No degradation issues in cold garage environments
- Reliability: Zero warranty claims on our install base so far
- Grid trading: Works well with Octopus Flux and other time-of-use tariffs
- Customer satisfaction: Those who chose Sigenergy for value have been pleased with the performance
One customer in Hailsham installed an 18 kWh Sigenergy system (2 × 9 kWh modules) alongside their existing solar array. They're now achieving 85% self-consumption and have reduced grid import from an average of £120/month to £25/month.
Installation Considerations
Planning a Sigenergy installation? Here's what to consider:
- Space: Battery modules stack vertically. An 18 kWh system (2 modules) is approximately 770mm × 270mm × 530mm
- Location: IP66 rated for indoor or outdoor installation. Works in garages, utility rooms, or external walls
- Ventilation: LFP batteries generate minimal heat, but adequate airflow is still recommended
- Compatibility: Designed to work with Sigenergy Energy Controllers (hybrid inverters)
- DNO notification: We handle all G98/G99 paperwork as standard
- Three-phase option: If you have a three-phase supply, the dedicated three-phase inverters (10-30 kW) provide balanced power
Sigenergy vs Competitors
Here's how Sigenergy stacks up against the alternatives we install:
| Brand | 18 kWh System Cost | Warranty | Best For |
|---|---|---|---|
| Sigenergy | £6,000-£7,500 | 10 years | Value-focused, larger systems, outdoor install |
| Fox ESS | £7,000-£9,000 | 10 years (registered) | Budget-conscious, modular flexibility |
| Anker Solix X1 | £9,500-£12,000 | 10 years | Premium finish, aesthetics priority |
The Verdict
Sigenergy won't win any beauty contests or brand recognition polls, but it delivers where it counts: reliable performance at a competitive price. If you're practical about home energy storage — you want the kWh, not the brand cachet — Sigenergy deserves serious consideration.
We've been impressed enough with the real-world performance to continue recommending Sigenergy alongside more established brands. For larger installations especially, the pricing advantage compounds significantly.
As always, the right battery depends on your specific situation. We're happy to discuss all options during a site survey and help you find the best fit for your home and budget.
Get a Quote
Interested in Sigenergy or want to compare it against other options? We can assess your property, discuss your energy goals, and provide quotes for different systems. Contact us for a free survey and consultation.
Lee Standell
Solar Energy Specialist at Eastbourne Energy