Batteries

How long do solar batteries last? Warranties, wear and what to check

Guides · Homerise team · Reviewed by Joern Haake · Published 5 November 2026 · Rebate figures verified 22 October 2026 · How we write guides

The short answer

The only lifespan a maker puts in writing is the warranty, and for the home batteries sold in Australia it is usually 10 years, promising that the battery still holds about 70% of its capacity at the end. Many warranties also stop early once a set amount of energy has passed through the battery (the throughput limit), so how hard the battery works matters as much as its age (warranties as checked on 15 October 2026; rules as of 22 October 2026).

What does a 10-year battery warranty actually promise?

Two things, and they're separate. The product warranty covers faults: a battery or inverter that stops working is repaired or replaced. The performance warranty covers wear: every lithium battery slowly holds less energy, and the maker promises it won't fall below a set share of its starting capacity, usually 70%, within the term. A 15 kWh battery at 70% still stores about 10.5 kWh. So at 10 years a battery that is working exactly as warranted is smaller, not finished.

Most performance warranties add a second limit: the term ends at 10 years or when a set amount of energy has gone through the battery, whichever comes first. That limit is what decides whether your use counts as normal.

What is a throughput limit, and how far does it go?

Throughput is the total energy a battery delivers over its life, written in megawatt-hours (MWh). Divide it by the battery's usable size and you get the number of full charge-and-discharge cycles the warranty allows. A home battery that charges from solar by day and runs the house each evening does roughly one full cycle a day, less in winter. The table shows how far each maker's limit goes:

How far each warranty's throughput limit goes (from the makers' Australian warranties)
Battery	Throughput per kWh	Full cycles	At 1 cycle a day	At 1.3 a day (example)
Sungrow SBH / SBRno limit for daily self-use and backup; this limit is for other uses	about 2.8 MWh	about 2,800	about 7.7 years	about 5.9 years
Tesla Powerwall 3no limit for daily self-use and backup; this limit is for other uses	about 2.8 MWh	about 2,800	about 7.7 years	about 5.9 years
Alpha ESS SMILE	about 3.12 MWh	about 3,120	about 8.5 years	about 6.6 years
GoodWe ESA	about 3.5 MWh	about 3,500	about 9.6 years	about 7.4 years
Sigenergy SigenStor	about 3.7 MWh	about 3,700	about 10.1 years	about 7.8 years
Fox ESS EQ	about 4.2 MWh	about 4,200	about 11.5 years	about 8.9 years

The last column is an example: a battery that also exports in the evening, or is called on by a virtual power plant, can do more than one cycle on some days. Two makers (Sungrow SBH / SBR and Tesla) don't count throughput at all when the battery is used for daily self-consumption and backup; their limit applies to other uses, or to a mix that includes them. Check which category a VPP or trading plan falls into before you join one. Each brand's other warranty conditions are on its own page: see home batteries compared.

How many years will a battery really last?

Longer than its warranty, if it's looked after, but nobody can promise how much longer. Home batteries sold today are almost all lithium iron phosphate (LFP), a chemistry chosen for its long cycle life. Makers' datasheets quote cycle lives in the thousands, measured in a lab: for example, more than 6,000 cycles for SolaX's batteries and at least 8,000 for GoodWe's ESA modules. At one full cycle a day, 6,000 cycles is about 16 years. A real garage wall in a Queensland summer is not a lab, so treat those figures as a ceiling and the warranty as the floor.

What wears a home battery out faster?

Heat. Batteries age faster when they sit hot. Some warranties now say so: Sungrow's May 2026 warranty assumes the battery isn't kept above 35 °C or 40 °C for long stretches each year, and Alpha ESS asks for an ambient −10 to 50 °C out of direct sun. Shade, airflow and a wall that doesn't face the afternoon sun all help.
Extra cycling. Every evening export, VPP event or time-of-use top-up adds throughput. It can be worth it, but it uses up the warranty faster on batteries with an all-uses limit.
Sitting full or empty for long periods. The battery's own software manages this day to day. If you're away for weeks, leave the system running rather than switching it off.
No internet. Several warranties need the battery online so the maker can see how it's used; offline for long enough, the cover can shrink. Keep the wifi or 4G link working and the app connected.

Does a battery last long enough to pay for itself?

That's the real question behind the lifespan. A 15 kWh battery costs about $9,000 to $14,500 installed after the federal battery rebate (October 2026); the rebate takes about $3,663 off that size (as of 22 October 2026). Spread over a 10-year warranty, that's about $900 to $1,450 a year before any savings. Whether the savings beat it depends on your bill, your tariff and how you use the battery: see is a home battery worth it, and for the size that fits your evenings, what size battery do you need.

What happens when a battery reaches the end of its life?

Usually nothing dramatic: it keeps working with less capacity, so it covers less of the evening. You can keep using it, add modules if the system still supports them (added modules are often warranted from their own install date), or replace it. A battery that's faulty within the term is a warranty claim through your installer. When a battery is eventually removed, ask the installer how it will be taken away and recycled; lithium batteries must not go in household bins.

What to check in a battery quote

The warranty term and the capacity it promises at the end (for example 70% at 10 years).
Whether there's a throughput limit, how many MWh, and whether it applies to how you plan to use the battery (VPP, evening exports).
The conditions: internet connection, registration at commissioning, temperature range, and who must install it.
Where the battery will go, and whether that spot stays out of direct afternoon sun.
Who you claim through: usually the installer first, then the maker.

More on comparing batteries: how to choose a home battery.

Questions people ask

How long do solar batteries last in Australia?

Most home batteries come with a 10-year warranty that promises about 70% of the original capacity at the end, or a throughput limit, whichever comes first. With care they often keep working beyond that, holding less energy each year.

What does 70% capacity at 10 years mean?

The maker promises the battery will still hold at least 70% of the energy it held when new. A 15 kWh battery would still store about 10.5 kWh at the end of the warranty.

Does joining a VPP shorten my battery's warranty?

It can. A VPP adds cycles, and on batteries whose warranty has a throughput limit for all uses, that limit is reached sooner. Some makers don't cap self-consumption but do cap other uses. Check which applies before you join.

Is it worth replacing an old battery?

Only when its remaining capacity no longer covers your evenings and a new one would save more than it costs. A battery at 70% still works; adding modules can be an option if your system supports it.

Does the federal battery rebate depend on the warranty?

The federal battery discount applies to approved batteries installed by an accredited installer. It takes about $3,663 off a 15 kWh battery as of 22 October 2026; the warranty is the maker's and runs separately.

Sources

General information, not financial advice. Rebate rules change: figures on this page come from our rules table, last verified 22 October 2026. How we're paid: installers pay Homerise for introducing you. No brand or installer pays to be mentioned in a guide.