High-capacity three-phase storage
A 20 kW three-phase hybrid inverter with large 10.24 kWh battery modules, scaling from 21.08 kWh up to 94.86 kWh.
Solar Battery·ESY SUNHOME
ESY SUNHOME HM20 — Three-Phase High-Capacity Home Battery
The ESY SUNHOME HM20 is a three-phase, all-in-one home energy storage system that pairs a 20 kW hybrid inverter with large, stackable LFP battery modules. It is built for big three-phase Australian homes and properties that need substantial storage and whole-home backup across all three phases.
The HM20 scales with 10.24 kWh battery modules for a capacity from 21.08 kWh up to 94.86 kWh, so it can cover high-consumption homes, all-electric households and properties chasing energy independence. Its IP66-rated design is built for outdoor installation in Australian conditions.
This page explains what the HM20 is, who it suits, every key specification, what those numbers mean for your home, and the technical terms behind them, so you can decide with confidence before requesting a quote from Sunbridge Energy.
Why choose the ESY SUNHOME HM20 Home Battery
Whole-home three-phase backup
Backs up loads across all three phases during an outage, so three-phase appliances keep running — not just a few circuits.
95% depth of discharge
A 95% depth of discharge means almost all of the rated capacity is usable, maximising the energy you get from a large battery.
LFP safety, IP66
Built with LFP (lithium iron phosphate) cells and a multi-layer safety design, rated IP66 for worry-free outdoor installation.
Long ≥ 6,000-cycle life
Rated for at least 6,000 cycles, the HM20 is engineered for many years of daily cycling in a high-use home.
10-year warranty
Backed by a 10-year warranty guaranteeing at least 70% capacity retention over the term.
Who the ESY SUNHOME HM20 Home Battery is for
Large three-phase homes
Big, all-electric three-phase homes with high consumption that need substantial storage and 20 kW of output.
Energy independence
Households chasing maximum self-sufficiency that want large capacity — up to 94.86 kWh — to cover the evening, overnight and extended outages.
Whole-home three-phase backup
Properties that want backup across all three phases during outages, keeping three-phase appliances running.
High solar self-consumption
Homes with large solar arrays that want to store as much daytime generation as possible rather than exporting it cheaply.
Outdoor installation
Properties needing a weatherproof, IP66-rated battery suitable for outdoor mounting in Australian conditions.
Scalable investment
Buyers who want to start at 21.08 kWh and expand toward 94.86 kWh as their needs grow.
Key specifications
Battery
- Chemistry
- LFP (LiFePO₄)
- Battery module
- 10.24 kWh each
- Depth of discharge (DoD)
- 95%
- Capacity range
- 21.08 – 94.86 kWh
- Cycle life
- ≥ 6,000 cycles (25 °C)
- Ingress protection
- IP66
Inverter & power
- Inverter type
- Three-phase hybrid (all-in-one)
- Rated output power
- 20 kW
- Output frequency
- 50 / 60 Hz
- Anti-islanding protection
- Yes
Warranty
- Warranty
- 10 years
- Performance
- ≥ 70% capacity retention
Specifications are based on the ESY SUNHOME residential ESS datasheet. Exact figures depend on the chosen configuration; Sunbridge will confirm the right setup for your property.
What the numbers mean for your home
95% depth of discharge
Depth of discharge (DoD) is how much of the battery you can use. At 95% DoD, about 95% of each 10.24 kWh module is usable, while a small reserve helps protect long-term battery health.
Up to 94.86 kWh capacity
That is a very large amount of storage — enough to carry a high-consumption home through the evening and overnight, ride through extended outages, or move largely off-grid.
Three-phase whole-home backup
In a three-phase home the battery can back up loads across all three phases during an outage, so three-phase appliances keep working — not just single-phase power points.
≥ 6,000 cycle life
One cycle is roughly one full charge and discharge — about a day of use. At 6,000+ cycles, the HM20 is built for well over a decade of daily cycling.
IP66 rating
Rated for full outdoor installation — dust-tight and protected against powerful water jets — so it can be mounted outdoors.
Anti-islanding protection
A safety function that stops the system feeding the grid during an outage, protecting line workers while still allowing safe backup to your home.
A deeper look at the technology
Serious storage for large three-phase homes
The HM20 pairs a 20 kW three-phase hybrid inverter with large 10.24 kWh LFP battery modules, scaling from 21.08 kWh up to 94.86 kWh. That makes it suited to big, all-electric homes and properties that need substantial whole-home storage and high output.
As a true three-phase system, it can back up loads across all three phases during an outage, keeping three-phase appliances running rather than just a handful of circuits.
Safety and outdoor durability
The HM20 uses LFP (lithium iron phosphate) chemistry with a multi-layer safety design and anti-islanding protection, in an IP66-rated enclosure built for worry-free outdoor installation.
A long cycle life of ≥ 6,000 cycles and a 95% depth of discharge mean strong everyday usable capacity and a long service life, even under heavy daily use.
A closer look
Key terms explained
Shopping for a home battery means wading through technical jargon. Here is what the most important terms on this page actually mean.
kW vs kWh
A kilowatt (kW) measures power — how much the system can deliver at any instant. A kilowatt-hour (kWh) measures energy — how much it can store or deliver over time. A 10 kW / 20 kWh system can push 10 kW and hold 20 kWh, roughly enough to run a 10 kW load for two hours.
LFP (LiFePO₄)
Lithium iron phosphate, a lithium battery chemistry prized for thermal stability, safety and long cycle life. It is the preferred chemistry for residential storage.
Hybrid inverter
A single inverter that manages solar panels, the battery and the grid together, rather than needing separate solar and battery inverters.
High-voltage (HV) battery
A battery built from many cells in series to reach a high system voltage (often 400–800 V). Higher voltage means lower current for the same power, which reduces losses and can improve efficiency.
Depth of Discharge (DoD)
How much of a battery’s capacity you can safely use. 95% DoD means 95% of the rated capacity is usable; 100% means all of it.
Usable vs nominal capacity
Nominal capacity is the battery’s total energy on paper; usable capacity is what you can actually draw after the DoD limit. Always compare batteries on usable kWh.
Cycle life
The number of full charge-and-discharge cycles a battery can perform while staying within its warranty performance. Roughly one cycle per day of normal use.
Round-trip efficiency
The share of energy you get back out of the battery compared with what you put in. Higher efficiency means less energy lost as heat during storage.
C-rate (1C)
How fast a battery charges or discharges relative to its capacity. 1C means it can charge or discharge its full capacity in about one hour.
MPPT
Maximum Power Point Tracking — circuitry that constantly tunes each solar string to extract the most power. More MPPTs let panels on different roof faces perform independently.
Three-phase vs single-phase
Single-phase supply has one active wire and suits most smaller homes; three-phase has three and suits larger or all-electric homes with heavier loads. The battery must match your supply type.
Unbalanced load
In a three-phase home, when the three phases draw different amounts of power. A system that supports unbalanced loads can back up appliances even when the phases are uneven.
Backup / anti-islanding
Backup power runs your home during a grid outage. Anti-islanding is the safety function that stops the system feeding the grid during an outage, protecting line workers.
VPP (Virtual Power Plant)
A network of home batteries an energy provider can call on at peak times. Joining a VPP can earn you payments or credits for sharing stored energy back to the grid.
IP rating (e.g. IP65)
An Ingress Protection rating. The first digit is dust protection (6 = dust-tight), the second is water protection. An IP65/IP66 unit can be installed outdoors.
Rebates, payback and savings
Home battery storage can be eligible for government rebates and incentives, which change over time and vary by state and household. For a large system like the HM20, the right rebate and a correctly sized design can have a significant impact on payback.
Sunbridge handles rebate guidance as part of the quote process: we check current eligibility, factor available incentives into your system design, and show you the expected payback based on your actual usage. See our battery rebate guidance for more, and we will confirm what applies to your address when you request a quote.
Read our battery rebate guidance →
Installation and support by Sunbridge
Sunbridge designs every HM20 system around your property rather than selling a fixed package. We start by analysing your electricity bills and smart-meter usage data to understand how and when you use power, then size the inverter and battery to match.
Installation is carried out by accredited installers to Australian standards, including three-phase switchboard and backup configuration, commissioning and testing, and a full handover so you know how to use the ESY SUNHOME app. We also provide ongoing support and monitoring for the life of the system.
Warranty
The ESY SUNHOME HM20 is backed by a 10-year warranty. Over the warranty term, the battery is guaranteed to retain at least 70% of its original usable capacity, or until it reaches its guaranteed energy throughput, whichever comes first.
These are the manufacturer’s terms; your guarantees under the Australian Consumer Law apply in addition. Sunbridge confirms the current warranty terms for your configuration and registers the warranty on your behalf as part of the installation.
Frequently asked questions
How much capacity does the HM20 have?
The HM20 uses 10.24 kWh battery modules for a capacity from 21.08 kWh up to 94.86 kWh, suited to large, high-consumption three-phase homes.
Is the HM20 single-phase or three-phase?
The HM20 is a three-phase, 20 kW system. For single-phase homes, ESY SUNHOME’s HM5 is the single-phase option.
What is the depth of discharge?
The HM20 has a 95% depth of discharge, so about 95% of each 10.24 kWh module is usable.
Can it back up my whole home?
Yes. As a three-phase system it can back up loads across all three phases during an outage, with anti-islanding protection for safety.
Can it be installed outdoors?
Yes. The HM20 is rated IP66 — dust-tight and protected against powerful water jets — so it is suitable for outdoor installation in Australian conditions.
What battery chemistry does it use?
LFP (lithium iron phosphate / LiFePO₄), the most thermally stable mainstream lithium chemistry, with a multi-layer safety design.
How long is the warranty?
A 10-year warranty guaranteeing at least 70% capacity retention, with a ≥ 6,000-cycle rating. Australian Consumer Law guarantees also apply.
Interested in the ESY SUNHOME HM20 Home Battery?
Talk to Sunbridge Energy about design, installation and a quote tailored to your home.