Switching to solar? You might be considering a battery too, but before you do, get an idea of how long a solar battery will last.
- What Is the Typical Lifespan of a Solar Battery?
- Measuring a Battery’s Lifespan
- Which Type of Solar Battery Has the Longest Lifespan?
- How Can I Increase a Battery’s Lifespan?
- Don’t Run Too Few or Too Many Cycles
- When Does a Battery Need To Be Replaced?
- Will Solar Battery Lifespans Increase?
- How Long Do Solar Battery Warranties Last?
If you’re thinking of getting a solar battery, first off, good for you – you’re going to benefit from lower energy bills, reduced carbon emissions, and less reliance on the grid for your electricity.
One factor you’ll want to know more about before you get a solar battery though, is how long it’ll last.
Solar panels last 30-40 years these days, so you’re going to want to know if you’ll need to buy multiple batteries within this lifespan. Spoiler for what’s to come: yes, you’ll need more than one solar battery, and we’ll tell you how many in this article.
You’ll also learn about how to choose the best battery for your needs, what affects a battery’s lifespan, and how you can maximise the longevity of a battery.
PS We offer MCS-certified solar panel installation nationwide. Simply answer these questions, get your fixed price and arrange your free design.
Key Points:
The majority of solar batteries last 10-12 years.
Lithium-ion batteries are the most common type of battery storage in the UK.
You’ll need a minimum of two batteries within the lifespan of a solar panel system.
Regular maintenance and monitoring are great ways to increase your battery’s lifespan.
Most warranties for solar batteries last 10 years.
What Is the Typical Lifespan of a Solar Battery?
Solar batteries last between 10 and 12 years, which is a little under half the usual lifespan of solar panels. This means you’ll need to buy at least two batteries before your solar panels reach the end of their effectiveness.
What this doesn’t mean is that your solar batteries will stop working entirely after these 10-12 years. Instead, their total capacity will degrade as will their ability to hold charge. So you can still use them after this point, they just won’t be able to provide the same power as they did when they were new.
Read more:
Measuring a Battery’s Lifespan
The more accurate way to measure how long a solar battery will last is to look at the number of cycles it can perform. A cycle in a solar battery is how many times it’s fully charged up and then discharged (a discharge is when you use the battery, simply put).
The best solar batteries have between 6,000 and 10,000 cycles and most households with battery storage will cycle through their battery one-two times per day (two cycles a day is more likely if you’re exporting excess electricity via the Smart Export Guarantee).
Which Type of Solar Battery Has the Longest Lifespan?
The type of battery storage with the longest lifespan is lithium-ion, which can comfortably last 10-12 years with little degradation in performance.
Lead-acid batteries, the closest rival to lithium-ion and generally the cheaper of the two, typically last half this (and some can last as few as three years).
This is why most manufacturers have switched to using lithium-ion for their solar batteries.
How Can I Increase a Battery’s Lifespan?
Treat your battery with the care and respect it deserves, and it can last longer and potentially save hundreds of pounds more on your energy bills per year. Here’s how:
Install your battery in a cool, dry part of your home
Use the recommended Depth of Discharge (DoD)
Regularly maintain and monitor your battery
Stick to one or two cycles maximum
Install in a Cool, Dry Location
If you can, get your battery installed in a well-insulated and well-ventilated room in your home. Sure, some models such as the Tesla Powerwall 3 can be installed outside (and work just fine there too), but batteries will almost always prefer to be inside and dry (wouldn’t you?).
Also, it might not regularly dip below freezing in the UK, but it can still get pretty cold outside, which’ll raise internal resistance within a battery. This means your battery’s ability to either release or hold onto energy will be reduced.
Stick To The Recommended Depth of Discharge
All solar batteries have a Depth of Discharge, which is a limit of how much of a battery’s full charge you should use before charging it up again. For example, if a battery’s Depth of Discharge is 90%, it’s best to only use a maximum of 90% of its maximum capacity before charging it again (either with your solar panels or with electricity from the grid).
For a 10 kilowatt hour (kWh) battery, that gives you 9kWh to use before you should recharge it.
We recommend sticking to the Depth of Discharge suggested by your battery’s manufacturer, because ignoring it can significantly reduce a battery’s lifespan.
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Battery Maintenance and Monitoring
You’ll have your storage battery for a little over a decade, so it’s a good idea to learn how to monitor and maintain it. This is pretty simple these days as most models come with easy-to-understand apps that gives you all sorts of useful information including:
Current and past charge levels
How long your battery can power your home for
What source is currently charging your battery (solar, grid electricity, or otherwise)
Time it takes to charge
Battery monitoring apps let you discover when there’s a problem with your battery too, so you can get it fixed as quickly as possible.
In general, keeping an eye on your battery is one of the most important steps you can take to make it last as long as possible.
Don’t Run Too Few or Too Many Cycles
Solar batteries prefer an optimal number of cycles per day. Too few cycles, and your battery can start to degrade in a sort of use-it-or-lose it scenario.
Too many cycles and you risk wearing your battery out and shrinking its lifespan, or causing it to break down entirely.
It’s best to stick to one-two cycles daily. Once per day is normal for most households with solar panels, though if you’re exporting via the Smart Export Guarantee, two cycles will be most profitable.
When Does a Battery Need To Be Replaced?
Stick to the advice above, and your battery will comfortably last 10-12 years, but when it’s time to replace it, your battery will give you some signs. Here’s what to look out for:
Your battery charges really slowly. If your battery takes ages to charge up, it suggests its ability to hold charge from either your solar panels or the grid is degrading. This also means your battery will likely discharge quicker than usual too.
It takes ages for your battery to charge devices. A battery taking ages to charge things like laptops or other electrical appliances likely means the voltage has dropped. If this can’t be fixed, you probably need a new solar battery.
The battery depletes too quickly. A battery that powers your home for less time that it normally would is a sign it could need replacing. The app that comes with your battery will give you information on how long your battery should normally last.
You can see visible signs of damage to the battery. If you can see bumps or holes appearing on your battery, or there are leaks, it’s going to be pretty obvious that the time to replace it is nigh. Additionally, a leaky battery can cause damage to your home.
Explore a Battery Storage Case Study: Check out an insightful Q&A session featured in one of our detailed case studies on battery storage. Hear directly from a Heatable customer in the UK and gain valuable perspectives on their experience here.
The image above features a Tesla Powerwall 3 installation performed by our team of Tesla-certified installers at Heatable.
Will Solar Battery Lifespans Increase?
Technology in solar batteries is improving all the time, which is leading to longer lifespans overall.
Many manufacturers are working to increase the depth of discharge available on their batteries for example. A better depth of discharge means you can be more liberal with how much of a battery’s total capacity you can use, reducing the risk of damaging it from a complete discharge.
How Long Do Solar Battery Warranties Last?
Typical solar battery warranties last 10 years or so. As long as you stick to the manufacturer’s instructions for battery operation, you’ll be covered if the battery breaks down within the warranty period.
Something to look out for are warranties specifying the number of cycles a battery can run before the warranty runs out. Basically, if a battery’s warranty allows for a maximum of 6,000 cycles, once you’ve exceeded this, you’ll no longer be protected if the battery breaks down.
However, many manufacturers are starting to offer warranties with unlimited cycles. Tesla’s Powerwall 3 is one such battery, so you can cycle it till your heart’s content within the standard 10-year warranty period!
Next Steps For Your Battery Journey:
When planning to install battery storage for your home, there are several important factors to consider. Make sure to refer to the following guides to help you make informed decisions:
To dive deeper into these topics, head over to our advice section, check out our YouTube channel for informative videos, or read a customer case study to see how others have benefited from their battery installation.
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