The short version
- Both batteries use safe LFP chemistry and both qualify for the federal Cheaper Home Batteries rebate.
- ESY Sunhome is the value pick: a simple all-in-one at a lower cost per kWh, ideal for straightforward self-consumption and backup.
- Sigenergy SigenStor is the premium pick: AI software, integrated bidirectional EV charging and a modular, future-proof design.
- Because we install both, our recommendation is based on your home and budget, not on what we happen to stock.
Two batteries come up again and again with Sydney homeowners right now: the premium, modular Sigenergy SigenStor, and the value-focused all-in-one ESY Sunhome. We install both. That matters, because most comparison articles are written by a company that only sells one of them. We fit whichever is genuinely right for your home, so this is the honest version.
Sigenergy vs ESY Sunhome at a glance
| What matters | ESY Sunhome | Sigenergy SigenStor |
|---|---|---|
| Positioning | Value, all-in-one | Premium, modular flagship |
| Cell chemistry | LFP (lithium iron phosphate) | LFP (lithium iron phosphate) |
| Design | All-in-one tower, inverter built in | Modular "5-in-1" stack, inverter built in |
| Usable capacity | 5.12 kWh modules, approx 5 to 30 kWh single-phase | 5.2 / 7.8 kWh modules, approx 5 to 48 kWh per stack |
| Phases | Single and three phase | Single and three phase |
| Blackout backup | Yes, fast switchover | Yes, via the Sigen Gateway |
| EV charging | Separate charger | Integrated DC, bidirectional (V2H / V2G) |
| App and software | Functional, still maturing | Advanced, AI-driven (mySigen) |
| Warranty | 10 years | 10 years |
| Best for | Value, simple self-consumption | Future-proofing, EVs, expandability |
ESY Sunhome: the value all-in-one
The ESY Sunhome is an all-in-one tower with the hybrid inverter built in, so it arrives as fewer separate boxes on your wall. It uses proven LFP cells, the safest and most common chemistry for home storage, and stacks from a single 5.12 kWh module up to around 30 kWh on single phase, with much larger three-phase configurations available for big homes.
Where it wins
- Price per kWh. ESY consistently undercuts the premium brands, which makes it a strong choice when the goal is simple bill reduction and you do not need every advanced feature.
- Genuinely all-in-one. Inverter and battery in one unit means a clean, simple install.
- Solid, safe hardware. LFP chemistry, full backup capability and a 10-year warranty.
Where it asks a compromise
- Software is the weak point. The hardware is reliable, but the app and smart-control features are less polished than the premium players. If you want set-and-forget self-consumption, that is fine. If you want deep tariff optimisation, it is worth knowing.
- Younger in Australia. ESY has battery heritage overseas but a shorter local track record than some rivals.
Who it suits: the value-focused homeowner who wants a safe, capable battery for self-consumption and backup, at the keenest sensible price, without paying for features they will not use.
Sigenergy SigenStor: the premium, future-proof flagship
The Sigenergy SigenStor is a modular system that Sigenergy markets as "5-in-1": a hybrid solar inverter, the battery, the battery power electronics, an optional integrated DC EV charger, and the energy management brain, in one stackable tower. It uses LFP cells, stacks from around 5 kWh up to roughly 48 kWh per stack (and more in parallel), and is available in single and three phase. Backup is handled by adding the Sigen Gateway.
Where it wins
- Integrated, bidirectional EV charging. This is the standout. The optional DC charging module supports vehicle-to-home and vehicle-to-grid, so your car can power your house. Almost nothing else at this level does it this cleanly.
- The smartest software in the class. The mySigen app uses on-board AI to optimise charging, discharging and tariffs, and it polls fast enough to genuinely chase savings.
- Modular and expandable. Start smaller and add capacity later without ripping out the core system.
- Strong independent reputation. Despite being new, Sigenergy placed second in the 2025 SolarQuotes Installers Choice Awards and rates highly with installers who fit it.
Where it asks a compromise
- Price. You pay a premium for the hardware and the features. For a simple self-consumption setup, that premium may be more than you need.
- Backup needs the Gateway. Whole-home backup is excellent but requires the separate Sigen Gateway, which adds to the build.
Who it suits: the homeowner who wants the best, plans to keep the home long term, owns or will own an EV, and values AI optimisation, expandability and a future-proof platform.
Side-by-side specifications
| Specification | ESY Sunhome | Sigenergy SigenStor |
|---|---|---|
| Architecture | All-in-one tower, inverter built in | Modular 5-in-1 stack |
| Chemistry | LFP | LFP (280Ah prismatic cells) |
| Module size (usable) | 5.12 kWh | 5.2 kWh or 7.8 kWh |
| Capacity range | Approx 5 to 30 kWh (single phase); much higher three phase | Approx 5 to 48 kWh per stack; expandable in parallel |
| Inverter | Single phase 5 / 6 / 12 kW; three phase 15 / 20 kW | Single phase 5 to 10 kW; three phase 5 to 25 kW |
| Cycle life | 6,000+ cycles | Backed to 10 years, 70% capacity retention |
| Warranty | 10 years | 10 years (battery and controller) |
| Backup | Yes, full backup, fast switchover | Yes, via Sigen Gateway, around 5 ms switchover |
| EV charging | Separate AC charger | Integrated DC, 12.5 / 25 kW, bidirectional |
| App | ESYsunhome app | mySigen app with built-in AI |
| VPP support | Selected VPPs (including Origin) | Selected VPPs (including Amber and AGL) |
| Origin | China, battery heritage since 2004 | China, founded 2022 by ex-Huawei solar leadership |
Performance, backup and VPP
Blackout backup. Both batteries can keep your home running through a grid outage and recharge from your solar while off-grid. Both switch over fast enough that you will barely notice the lights flicker. The practical difference is that Sigenergy uses the separate Gateway for whole-home backup, while ESY builds backup into the unit.
EV charging. This is the clearest gap. If you drive an EV, or will soon, Sigenergy's integrated bidirectional DC charging is a genuine reason to spend more. ESY pairs with a separate charger, which works perfectly well but is not the same single, intelligent platform.
Virtual power plants and tariffs. Both can join selected VPPs and earn from exporting stored energy at the right times. Sigenergy's broader VPP support and smarter software give it the edge for households that want to actively arbitrage energy prices.
Price, rebates and value
We do not publish fixed prices, because the right system is designed for your home rather than pulled off a shelf. As a rough 2026 guide, a mid-sized installed battery lands in the low to mid five figures before rebates, with the Sigenergy carrying a clear premium over the ESY for the same usable capacity. The ESY is the value pick; the Sigenergy is the flagship.
Both are CEC-approved and eligible for the federal Cheaper Home Batteries Program, which takes roughly 30% off the up-front cost through STCs based on usable kWh. From 1 May 2026 the incentive is about 6.8 STCs per usable kWh (in the order of $252 per kWh at typical STC prices), tiered down on larger systems, and it steps down again from 1 January 2027. In short: the rebate is at its most generous now and shrinks over time, so the maths favours installing sooner rather than later.
Which battery should you choose?
Choose the ESY Sunhome if…
- Your priority is the best value per kWh for bill reduction and backup.
- You want a simple, clean all-in-one install.
- You do not need integrated EV charging or deep tariff optimisation.
- You are comfortable with capable hardware and straightforward software.
Choose the Sigenergy SigenStor if…
- You want the best, most future-proof platform on the market.
- You own or plan to own an EV and want bidirectional charging.
- You value AI optimisation, expandability and strong VPP support.
- You are keeping the home long term and want to buy once.
Still unsure? That is exactly what our consultation is for. We will look at your roof, your bills and how you actually use power, and tell you honestly which of these two batteries earns its place on your home.
Frequently asked questions
Is Sigenergy better than ESY Sunhome?
Are both batteries eligible for the federal battery rebate?
Can I add more battery capacity later?
Which is better if I have an electric vehicle?
Are these batteries safe to install at home?
Do you install both Sigenergy and ESY in Sydney?
This comparison is general information for Australian homeowners and reflects publicly available specifications at the time of writing (June 2026). Exact models, capacities, warranty terms and pricing change, and the right system depends on your home. Pricing figures are indicative only and exclude site-specific factors. Always confirm current specifications and rebate eligibility for your specific configuration at consultation.