How long do solar batteries last?

For many solar users, adding batteries is one of the best ways to ensure that they’re making the most out of their entire solar system. Adding storage means being able to enjoy your clean, green power for longer.

But once you’ve made the investment, how long should you expect those batteries to actually last? Read on and discover the answers to common queries on battery lifetime, warranties, materials, maintenance and, of course, which batteries are the best for solar power.

How long do solar batteries last?

All batteries naturally degrade over time - it’s unavoidable. However, the degradation process for solar batteries is slow. 

You’ll typically find that solar batteries will last anywhere between 5 and 20 years, with factors like the type of battery, the intensity of use, and the environment determining where in that range your solar battery will fall.

What about warranties?

Good quality solar batteries from reputable manufacturers/suppliers will typically come with a warranty. Warranties serve as a good indication of how long you should expect your solar battery to last under normal conditions.

Typically, warranties last for 10 years. For example, PylonTech, our preferred supplier, provides a warranty of 10 years for their solar batteries. If the battery stops working optimally before the warranty expires, you can simply have it replaced - no loss incurred.

However, if the warranty on your solar battery expires, this doesn’t mean you should expect your solar battery to simply stop working one day. Solar batteries that are getting on in years are usually still capable of operation - they simply don’t charge or discharge as efficiently or as much as they once would.

This is the difference between a warrantied life of a battery and a useful life of a battery. Solar panels are similar - panels that are still in operation after their warrantied lifetime (typically 25 years) will still generate power, just more slowly, but possibly still being within its useful lifetime.

Solar batteries are similar, though in regards to storing and discharging their energy, rather than generating it.

What are the best batteries for solar power?

If you want the best solar batteries for your needs, the key is finding a) a reputable supplier and b) a reputable installer. 

A good supplier will provide solar batteries that are fit for purpose and will have the aforementioned warranties to provide a safeguard against faults.

A good installer will ensure that your batteries are properly, efficiently and safely integrated into your existing solar system and electricity grid.

Both supplier and installer are absolutely necessary to get the most out of your solar system.

In terms of the batteries themselves, you will have a slew of choices in manufacturer, capacity, discharge rate, and more. It can be overwhelming, but the biggest choice that you’ll have is the decision of what material the battery is made from.

In 2022, you will typically find three types of batteries on the market that are suitable for solar.

• Lead Acid. These are typically the cheapest solar batteries on the market and have been around for decades. However, they also tend to have a shorter lifespan and poorer discharge capability than the more modern types of battery. They’re a popular choice for homeowners who are planning to go off-grid and need lots of storage without lots of cost.
• Lithium Ion. Also called li-ion batteries, these are what the majority of homeowners and business owners use for solar storage. They’re lighter and more compact than lead acid, have a better depth of discharge, and enjoy a longer lifespan. In turn, they are more expensive - you get what you pay for.
• Saltwater. These are the cutting edge of solar tech. These batteries don’t use heavy metals like the other types of battery do, relying instead on saltwater electrolytes. This makes them more easily recycled, but because they are so new and have relatively few manufacturers, they can be expensive and rare.

At ZEN, we typically encourage the use of lithium ion batteries in our solar systems. We feel that they are the best balance of performance and cost, particularly when coming from PylonTech, our chosen supplier.

What are the factors that affect the lifespan of a solar battery?

The primary material in the battery isn’t the only factor that determines its overall lifespan. Other considerations include:

Battery cycling frequency

A solar battery ‘cycles’ when the battery fully charges and then fully discharges. The more this happens, the shorter the lifespan of the battery.

The frequency of your battery cycling is determined by your daily energy needs and the size of the battery in question. The larger the battery and the lower the daily needs, the longer it takes to fully charge and fully discharge, and thus the fewer times it cycles. 

Most New Zealand homes will experience a battery cycling about once or twice every day, so it still happens even with typical daily use. This is why sizing your solar batteries correctly is so important for longer lifespans. You don’t want more cycles than you need.

Temperature

Solar batteries are designed to operate within specific temperature ranges. If they are forced into high temperatures, they will not only lose performance, but will shorten their lifespan as well. The same can be said for cool temperatures for some batteries. 

This highlights the need for a reputable solar installer who will be able to tell you the best placement for your batteries to mitigate temperature influences.

Maintenance 

One of the appeals of a solar power system is that it’s mostly set and forget - there’s little maintenance involved other than hosing down the solar panels every so often to clear off the dirt.

That said, some maintenance is still required to ensure the full lifetime of your solar battery. Every producer will have slightly different expectations, so it’s best to refer to your manual for the specifics. 

Your installer should also be able to tell you what you’ll need to do to maintain your batteries. 

With the right materials, the right environment and the right maintenance, solar batteries can last decades with only a small drop in performance.

Want to find out more about solar power storage or systems? Get in touch with the team at ZEN Energy and let us help you find the right batteries for your panels.

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