For many Australians thinking about switching to solar energy or adding to their solar system set-up, a question often arises: “How long do solar batteries last?”. It’s a common question not least because solar batteries come at a considerable up-front cost, which can range from $4,000 to $8,000 for a four kiloWatt-hour battery.
The answer to the question of what lifespan you can expect your solar battery to have requires a look at the intricacies that determine how long it will last. Let’s explore the factors that impact the durability of solar batteries and what you can expect in terms of their longevity.
What factors influence solar battery lifespan?
Home solar battery technology
There are two common technologies that underpin solar batteries: lithium-ion and lead-acid. Lithium-ion technology is a more recent innovation that’s overtaken lead-acid batteries in the solar space. As well as having other advantages, such as being lighter, requiring less maintenance and having a greater ‘depth of discharge’ – read on for more info on depth of discharge, or DOD – lithium-ion batteries tend to have a longer lifespan of 10-15 years and often come with a 10-year warranty, while lead-acid solar batteries are typically said to last 5-10 years, although there are no doubt outliers in both categories that are longer- or shorter-lived than their counterparts.
There is another type of home solar battery, called a flow battery, that’s relatively new to the industry. According to Plico Energy, flow batteries are based on vanadium technology and can last from 15-25 years but are so far less popular than their lithium-ion competitors because they’re more expensive and need to be stored securely due to the toxic fluid they need to function.
Battery depth of discharge
Every solar battery has what’s called a depth of discharge, which is expressed as a percentage and refers to how much of energy the battery has stored can be discharged, or used, without damaging the battery itself. The Journal of Energy Storage explains it simply: “If the DOD of a battery is 0%, this means that it is 100% charged; if the DOD of a battery is 100%, the battery is flat”.
One of the reasons lithium-ion batteries are popular is because they allow a greater depth of discharge – of up to 95% – without damage to the battery than lead-acid batteries, which have a DOD of about 50%. Most modern solar batteries won’t allow you to discharge it to 100% to prevent accidental damage but repeatedly exceeding the recommended DOD of your battery is likely to shorten its working life.
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Solar battery usage patterns
The saying may be ‘use it or lose it’ but when it comes to solar batteries, how you use it impacts how long the battery lasts. Every battery has a ‘cycle life’, which is how many times it can be charged and discharged, and how often it repeats this cycle has an impact on how long the battery will last. The RACV explains that the standard cycle life of a solar battery is about 6,000 cycles, or a charge and discharge every day for 10 years – another reason for the common 10-year warranty on batteries.
Batteries subjected to deep cycling, where they undergo frequent charging and discharging to close to their DOD, can deteriorate more quickly than solar batteries that don’t.
The environmental conditions
Exposure to extreme heat or cold or to extreme temperature fluctuations can impact a solar battery’s performance and longevity. It’s important that your solar battery is protected from harsh weather conditions, so while many solar batteries can be placed outside, it must be shielded from moisture and direct sunlight. A well-ventilated space is recommended if your battery is stored indoors.
Compare solar electricity plans in your state
Here are some of the cheapest solar-specific deals from the retailers on our database. These costs are based on the Ausgrid network in Sydney but prices will vary depending on your circumstances. We show one product per retailer, listed in order of lowest price first. Annual price estimates assume general energy usage of 3900kWh/year for a residential customer on a single rate tariff. Price estimates exclude solar feed-in tariff credits. These are products from referral partners†. Our database may not cover all deals in your area, and please check retailer websites for up to date information.
Here are some of the cheapest solar-specific deals from the retailers on our database. These costs are based on the Citipower network in Melbourne but prices will vary depending on your circumstances. We show one product per retailer, listed in order of lowest price first. Annual price estimates assume general energy usage of 4000kWh/year for a residential customer on a single rate tariff. Price estimates exclude solar feed-in tariff credits. These are products from referral partners†. Our database may not cover all deals in your area, and please check retailer websites for up to date information.
Here are some of the cheapest solar-specific deals from the retailers on our database. These costs are based on the Energex network in Brisbane but prices will vary depending on your circumstances. We show one product per retailer, listed in order of lowest price first. Annual price estimates assume general energy usage of 4600kWh/year for a residential customer on a single rate tariff. Price estimates exclude solar feed-in tariff credits. These are products from referral partners†. Our database may not cover all deals in your area, and please check retailer websites for up to date information.
Here are some of the cheapest solar-specific deals from the retailers on our database. These costs are based on SA Power network in Adelaide but prices will vary depending on your circumstances. We show one product per retailer, listed in order of lowest price first. Annual price estimates assume general energy usage of 4000kWh/year for a residential customer on a single rate tariff. Price estimates exclude solar feed-in tariff credits. These are products from referral partners†. Our database may not cover all deals in your area, and please check retailer websites for up to date information.
Battery care and maintenance
Ensuring your battery is well maintained is vital to extending its lifespan. These are some of the care recommendations made by solar battery experts.
Regular inspections: Looking out for wear and tear can prevent further deterioration of your battery, just as it does your car when you get regular services. Solar Battery Group recommends checking in particular that the battery terminals are clean, dust-free and showing no signs of corrosion.
Temperature control: Solar Quotes highlights “ to mitigate the risks of overheating or freezing, both of which can accelerate battery degradation”.
Firmware updates: Evergreen Electrical says that ensuring your solar battery’s firmware is up to date is crucial. Manufacturers may release firmware updates to bolster performance and address potential issues, underscoring the importance of staying abreast of these updates.
So how long will my solar battery last?
The lifespan of your home solar battery hinges on all of the above factors. While lithium-ion batteries typically offer a longer lifespan than their lead-acid counterparts, proper care and maintenance, while not intensive, is still needed if you want to get the longest life possible from your battery. With the right attention, you should expect to get many years of use from a solar battery but still anticipate that you may have to replace it before you need to replace your solar panels.
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