Three key players in the Cheaper Homes Battery Program

In this in-depth review, solar installer Mark Wright examines three batteries approved for use in Australia’s solar PV rebate scheme.

In July this year, the federal government announced the Cheaper Homes Battery Program. The program is administered by the Department of Climate Change, Energy, Environment and Water (DCCEEW) with funding allocated by the Clean Energy Regulator (CER), which is responsible for the solar PV rebates.

The program provides the upfront cost for new or existing solar power systems to install a CEC-approved battery between 5 and 100 kWh (although only the first 50 kWh is eligible). While many residential customers who install a 10 kWh battery on a solar PV system would typically see a rebate of approximately $3500 applied, in rural areas, where there is no reliance on a grid connection, storage would typically be much larger.

My company, Stand Alone Power Systems, has performed many rural off-grid installations, which typically have about 50 kWh battery capacity.

The rebate applied to a 50 kWh battery installed in an off-grid solar power system is approximately $18,000+. There are a few eligibility requirements; more on this at the end of this review. This article discusses three lithium batteries that are designed for both grid-connected and off-grid solar PV systems.

BYD B-BOX LV FLEX

BYD began making batteries in 1995 for the global market. The company entered the EV market in 2022 after establishing a global reputation as a lithium battery manufacturer and supplier to many EV companies. BYD’s product range consists of both residential and commercial batteries.

The BYD B-BOX LV FLEX is a 48-volt 5 kWh battery. In terms of its flexibility, the LV Flex can be stacked up to 64 units, equivalent to 320 kWh, making it ideal for off-grid power systems. In this example, the BYD LV Flex is an excellent choice of product because it allows for future expansion with relative ease — especially where a customer may already have an existing solar PV system and have a surplus of solar generation, which has been a trend with many solar companies selling larger systems due to attractive rebates at the time.

Another great feature of the LV Flex is the number of inverter manufacturers it’s capable of working with, most of which are approved by the CEC, meaning that this battery is eligible for the cheaper home battery rebate.

BYD’s continual expansion in Australia is expected to solidify its position as a major player in the battery storage and EV markets. The BYD EV Sealin 7 SUV has knocked off the Tesla Model Yas in Australia (July).

ZYC’s SIMPO 5000

ZYC, a Chinese-based battery manufacturer, has had a presence in the energy storage industry for over 10 years, specialising in advanced off-grid energy storage systems. It maintains distribution networks across Europe, Australia and Africa. In late 2023, ZYC launched its flagship SIMPO 5000 battery (5.12 kWh) LiFePO₄ module, which is compact yet scalable. In terms of scalability, the SIMPO can be expanded up to 80 units or 409 kWh in total capacity. ZYC’s influence in the Australian market is beginning to be felt.

The Simpo 5000 is suited to both smaller (<10 kWh) residential systems and larger (>50 kWh) commercial off-grid systems. ZYC has installed systems in partnerships with local off-grid solar installers. The ZYC Simpo 5000 is CEC-approved for the Cheaper Home Battery Program and is warrantied for 10 years.

It will be interesting to see how the ZYC company positions itself against other, more established battery manufacturers.

PowerPlus eco4840P

PowerPlus is Australia’s largest lithium battery manufacturer. Headquartered in Melbourne since 2017, the company designs and assembles imported LiFeP cells for a range of energy storage products for off-grid, hybrid and commercial systems.

The PowerPlus eco4840P is a 48-volt 4.7 kWh unlimited stackable battery. It is a popular option for off-grid installers in Australia because it is locally supported, designed for Australian conditions (being heat-tolerant and robust), and generally uses conservative ratings.

Due to their conservative ratings, it is fair to compare the eco4840P with the BYD and ZYC product range. All three have a 10-year warranty. The eco4840P is slightly more expensive than the Chinese brands for obvious reasons.

The greatest advantage of the eco4840P is that it is unlimited by the number of units that can be stacked, leading to an edge over its competitors (although it requires additional comms equipment). Also, the fact that the eco4840P’s physical dimensions and weight are more than BYD or ZYC suggests that its specifications may be very conservatively underrated.

The eco4840P has also partnered with many leading brands of Australian inverters; therefore, you would expect excellent local support for any size of off-grid system.

Image credit: iStock.com/Chris Gordon

Like any comparison between products, the devil is in the details. While all three products offer the same 10-year warranty, the BYD LV Flex warranty only applies to systems less than 50 kWh — above that, a commercial warranty applies, meaning that the installer must be an authorised BYD partner.

The other notable point in terms of specifications is that both BYD and PowerPlus claim a 60% usable capacity after 10 years, whereas ZYC claims a 70% capacity. It would be worthwhile seeing how long ZYC sticks around. Comparisons between cycle life are as follows:

PowerPlus Energy ECO4840P (4.7 kWh, LiFePO₄)

• Published cycle life (by DoD): (depth of discharge)
• 50% DoD: 7000–10,000 cycles
• 75% DoD: 4000–5,000 cycles
• 80% DoD: 3560–4,000 cycles
   

BYD Battery-Box LV FLEX / FLEX Lite (5.0 kWh module, LiFePO₄)

• Published cycle life: BYD does not state a cycle count for LV FLEX; it specifies usable energy at 100% DoD test conditions.
• What that means for 10 years: designed for daily cycling; actual life is governed by the throughput cap + 60% capacity guarantee rather than a published cycle number.
   

ZYC SIMPO 5000 (5.12 kWh, LiFePO₄)

• Published cycle life: >6000 cycles (at 25 °C)
• What that means for 10 years: >6000 cycles is well above 3650 daily cycles; the 70% SoH promise is a slightly stronger capacity retention than BYD’s.

Eligibility

Eligibility requirements for the Cheaper Home Battery Program for installations connected to the grid require that the system is virtual power plant (VPP)- capable. For systems off-grid, the eligibility requirements are that if the system is less than 1 kilometre from the grid, then it must be VPP-capable. For systems more than 1 kilometre from the grid, the cost of grid connection must be $30,000 or more (excluding trenches or overhead wiring to your home), or the system must be VPP-capable.

*Mark Wright is the founder of Stand Alone Power Systems (2006), which has been providing off-grid solar energy systems in Queensland and NSW for almost 20 years.

Top image credit: iStock.com/Kiara Bloom