How about Batteries?

How do battery systems work?

A grid connected battery is designed to store solar electricity generated during the day to be later used at night time in your home.

Batteries are popular for two main reasons:

Financial Reasons:  When you feed electricity into the electricity grid, you sell the surplus electricity to your retailer and get paid for it. The amount that your energy retailer will pay you is usually much less than the amount they charge you when you buy electricity from the grid. So instead of selling at a low price during the day and buying back at night for a high price, you can store the electricity in a battery during the day and use it at night.

Blackout Protection: Some battery systems are able to be used during a blackout. So you can have some level of electricity available when your neighbours are left in the dark. Generally the blackout mode is power limited and is therefore suited to essential appliances only. You probably wouldn’t run a three phase reverse cycle air conditioner but you can generally run lights, fridge, TV, microwave and computers.

Sonnen Batteries

Sonnen, a German energy storage pioneer founded in 2010, is renowned for its high-quality lithium iron phosphate (LiFePO4) home battery systems, which offer safety, longevity, and efficiency. While Sonnen batteries were once assembled in South Australia at the former Holden plant in Elizabeth from 2018 to 2022, production has since shifted back to Germany.

The company maintains a local presence in Adelaide for support and service, ensuring accessibility for Australian customers. This local office, backed by Shell’s 2019 acquisition, supports over 5,000 installations across Australia.

Sonnen batteries, like the sonnenBatterie Evo and hybrid 9.53, are highly regarded. The Evo, designed for Australian conditions, offers 10 kWh usable capacity, 5 kW continuous power, and a robust 10-year or 10,000-cycle warranty, guaranteeing 80% capacity retention. Its IP56 rating allows outdoor installation, withstanding temperatures from -10°C to 50°C, ideal for Australia’s climate. The hybrid 9.53, with expandable storage (5–15 kWh), suits varied household needs and integrates seamlessly with existing solar systems due to its AC-coupled design and built-in inverter.

Performance-wise, Sonnen batteries excel in reliability, with LFP cells from Pylontech (previously Sony) passing rigorous durability tests. They achieve up to 80% round-trip efficiency and support virtual power plants (VPPs) like sonnenConnect, earning users up to $24 monthly. Customer reviews on SolarQuotes and ProductReview praise the sonnenApp for real-time monitoring and energy independence, with some reporting near-zero grid reliance. However, drawbacks include a premium price ($12,000–$16,000 for 10 kWh) and occasional customer service issues, with complaints about warranty support and discontinued modular expansions.

Despite ceasing local manufacturing, Sonnen’s German-engineered batteries remain a top choice for Australian homeowners, especially with the federal solar battery rebate launching July 1, 2025, offering $3,300–$5,000 savings. Compared to competitors like Tesla Powerwall, Sonnen offers superior temperature resilience and warranty terms, though its power output (2.5–5 kW) may not suit high-energy homes. For those prioritizing safety, scalability, and VPP earnings, Sonnen is a solid investment, backed by a strong reputation and local support.

Enphase Batteries

Enphase is best known for its micro-inverters. However it also makes batteries.

The flagship Enphase IQ Battery 5P, a third-generation model, delivers 5 kWh of usable capacity with 3.84 kW continuous and 7.68 kW peak power, ideal for powering appliances like air conditioners or pool pumps. Its modular, AC-coupled design, featuring six embedded microinverters, ensures scalability and easy retrofitting with existing solar systems, especially Enphase microinverter setups. The IQ Battery 3T and 10T, with 3.36 kWh and 10.08 kWh capacities, offer flexibility for smaller or larger households.

Manufactured with lithium iron phosphate (LFP) cells, Enphase batteries prioritize safety and durability, operating from 0°C to 45°C, suiting Australia’s climate with indoor or outdoor installation (IP55 rating). A 15-year warranty or 6,000 cycles (60% capacity retention) outperforms many competitors, ensuring long-term value. The Enphase App enables real-time monitoring.

 

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LG Batteries

LG is a massive battery manufacturer and was one of the first home battery systems available in Australia.

The LG battery comes as a battery only and needs to be matched to a special solar hybrid inverter.

LG Chem, a South Korean leader in lithium-ion battery technology since 1947, offers its RESU (Residential Energy Storage Unit) line, popular in Australia for home solar systems. While LG Chem Australia, based in Melbourne, supports sales and service, the batteries are manufactured in South Korea, not locally. The RESU range, including the 10H Prime  and 16H Prime, uses nickel manganese cobalt (NMC) chemistry, delivering high energy density and 95% DC round-trip efficiency.

These batteries excel in Australia’s harsh climate, operating from -10°C to 45°C, though indoor installation (e.g., garages) is recommended to avoid warranty issues. With a 10-year warranty guaranteeing 70% capacity retention (or 22.4 MWh throughput), LG Chem batteries show only 16% capacity drop after three years, suggesting a 12–14-year lifespan. They’re compatible with inverters like SolarEdge and support virtual power plants (VPPs).

Compared to Tesla Powerwall, LG Chem’s RESU is 20–30% cheaper but has lower capacity.