Solar Batteries
9 May 2025
When it comes to converting to solar energy, the first question that comes to most minds is, How long do solar batteries last? And it’s a very legitimate concern, especially if you’re going to commit to an entire set of solar panels for your home or your business. The actual lifespan of a solar battery depends on several crucial factors. Battery life can be affected by its type, how often you use it, how deeply it discharges, and where you live.
Choosing between lead-acid batteries, lithium-ion batteries, or deep-cycle batteries—each has a different way of performing and a different length of time it is expected to last. This blog will examine what influences how well your solar battery options can last over time so you can understand how to decide which type of solar battery best complements your solar panel system.
How a solar battery is treated matters more than its age. Let’s analyse all the factors that affect battery lifespan.
How a solar battery is treated matters more than its age. Let’s analyse all the factors that affect battery lifespan.
Solar batteries must be maintained at an adequate temperature. Excess heat or cold can damage the battery and lessen its durability. Cold can reduce the battery’s operational efficiency, while higher temperatures cause the internal system to malfunction. Always store your battery correctly.
Depth of discharge is usually the amount of energy stored in a battery before it is recharged. The deeper the discharge in each cycle, the shorter the battery’s lifespan. Due to deeper discharges, lithium batteries are more resilient to wear and tear than lead-acid batteries.
Cycle life is the number of complete charge and discharge cycles a battery goes through. After a certain number of cycles, the battery’s performance decreases drastically. Batteries with higher cycle life perform better and longer and can go on for years without diminishing performance. Lithium batteries usually have more cycles, i.e., 4000 to 6000 cycles, than others. Use your battery in a balanced way to lengthen its lifespan.
Like any other electrical appliance, a solar battery craves proper care and attention, without which its lifespan can thoroughly deteriorate. Lead-acid batteries may need maintenance, such as water top-ups and terminal checks, but lithium batteries are low-maintenance. You must, however, conduct the essential maintenance of your battery by storing it properly and using it balanced.
Here’s how you can identify battery degradation from signs.
If your battery has started performing slowly and is not storing as much energy as it usually does, it indicates that its performance has decreased and is degrading gradually. In such cases, it won’t even charge fully.
Solar batteries are designed to run smoothly and be highly reliable. Still, if your battery regularly disrupts function and shuts down, it is a sign that it is malfunctioning and degrading. Your home will draw more power than it usually does.
All batteries get warm when charging and discharging, but excessive heating may indicate a problem and a shorter lifespan. This overheating causes a lifespan shortage and is also a safety issue.
Suppose your battery runs out of charge regularly and requires frequent recharging. In that case, it can be a sign that it is not storing energy properly and degrading its functionality and operations. The battery’s internal chemistry may be affected, which provides excess heat output and shortens its lifespan.
All batteries eventually run out of capacity, but if you notice a considerable loss of storage capacity, it is a sign that your battery needs replacement. In such cases, the battery will draw more energy, especially during the evening.
New-age batteries usually come with a Battery Management System, which is software that notifies you when there are issues such as overvoltage, overheating, or charging imbalance. If you are getting such warnings frequently, it is a sign that your battery needs to be changed to be safe.
Various types of solar batteries are available, each with pros, cons, and a lifespan.
Lead-acid batteries have existed for a long time, are widely used, and are mainly used in off-grid and budget solar systems. They are highly affordable and simple to install. They may require regular maintenance, but they are appealing due to their low cost. These batteries cannot manage deep discharges efficiently and safely. You can use them in energy or backup setups, but not daily.
Lithium-ion batteries, like those in Tesla Powerwalls or LG Chem Units, are among the most popular choices for new-age solar systems. They are preferred due to their higher depth of discharge, low maintenance requirements, high cycle life, and longer lifespan, which lasts 10 to 15 years.
Flow batteries are modern technological solutions that have become highly popular due to their ultra-long cycle life and scalability features. These batteries use liquid electrolytes and can provide a 20-year lifespan if proper care is taken. They are not flammable and can manage complete decomposition cycles without degradation.
Deep-cycle batteries, like solar systems, allow for consistent discharging and recharging. Unlike car batteries, which require quick bursts of energy, deep-cycle batteries provide a very consistent power supply for a long time. These batteries can be quickly discharged frequently without causing much damage.
Here’s how you can quickly improve the lifespan of your batteries
The chemistry of your battery depends mainly on temperature and is extremely sensitive. Excess heat can damage internal systems, and frigid temperatures can cause damage to battery cells and decrease their operational capacity over time. You must keep your batteries in a shady and well-ventilated area, like a garage, to maintain the ideal temperature.
Many people make the common mistake of fully charging and completely draining the battery. Such mistakes are not an ideal way to go about battery care. You must avoid extreme states of charge. You must keep your battery charged in the mid-range, i.e., 40–80%, to optimise it for longer. Such a setup decreases the battery’s stress and protects the internal systems. Various batteries let you set charge thresholds, ensuring your system stays optimised. This way, you can keep your battery health optimal for an extended period and prevent degradation.
You must always use the correct charging controller to calibrate your battery system and prevent overcharging or undercharging. These states can significantly decrease the life expectancy of your battery. You should ask your installer to modify the settings thoroughly during the setup process to keep your battery healthy. You must also conduct regular checkups to keep your battery in the best health possible.
Batteries create a lot of heat as they work. When you place them in a poorly ventilated area, this heat gets trapped and leads to internal degradation of the battery, affecting its performance throughout the day. To keep your battery free from any issues, keep it in a well-ventilated area and allow it to have sustained airflow for more extended durability. Ventilated storage allows for better performance throughout the day.
So, returning to the original question: How long do solar batteries last? They last 5-15 years on average, but the period can vary based on various factors, as we observed above. The maintenance of the battery, the storage, discharge depth, cycles, temperature, and other factors affect the battery’s lifespan. With meticulous care and attention, you can easily extend the lifespan of your battery without any concern or stress. Prevent capacity loss and damage to the internal system of your battery by using the tips mentioned above and enjoying the clean and green solar energy in your space.
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At Solahart, we’re proud to be leading Australia’s solar charge. Helping smart Aussies make a real difference to the planet, reducing their reliance on the grid, cutting their energy bills, and connecting them to their smart energy future.
Since 1953, we’ve been the trusted name in Australian solar, installing over a million solar hot water systems in over 70 countries, and over 1 million solar power panels in Australia.
