How long do solar batteries last?
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Installed system prices
Solar batteries are more popular than ever because they can keep your lights on during a power outage and maybe even save you a little extra cash on your energy bill. Unfortunately, they’re pretty expensive - the cheapest batteries will run you about $10,000, with most systems creeping closer to $15,000.
That’s a lot of money, so it’s important to know how long a battery will be able to power your home. The short answer is this: a solar battery will have a lifespan between 10 and 15 years. The reality is that your battery's lifespan depends on many factors.
Most solar batteries will last somewhere between 10 and 15 years.
It’s typical for a battery to come with a 10-year warranty, so you can most likely get at least a decade of use out of it. But just because the warranty is over doesn’t mean the battery suddenly stops working.
Solar battery technology is still relatively new, so there isn’t much information about how long home batteries will last beyond their warranty life. However, it’s safe to say that the battery will probably continue to store solar energy for at least another five years after the warranty term.
Keep in mind 10 to 15 years is a general estimate of how long a solar battery will last. Several factors will increase or decrease how many years you’ll be able to use your battery storage system.
Lithium-ion batteries fall into that 10 to 15-year lifespan we mentioned earlier. On the other hand, lead-acid batteries have a shorter lifespan of 4 to 8 years. So, if you choose to install lead-acid batteries, expect to replace your batteries more often than if you installed a lithium-ion battery.
Lithium-ion batteries are the most popular option among homeowners because they last so much longer than lead-acid batteries. Lead-acid batteries are more popular for off-grid solar installations. You can learn more about the difference between lead-acid and lithium batteries from solar expert Will White:
How you use your battery has a considerable impact on how long it will last. Think about the battery life of your cell phone; as you use it, you need to charge it more often. Solar batteries work the same way. As you use batteries, their storage capacity decreases, and they need to be recharged more often.
When thinking about how long a battery lasts, it’s better to think about it in cycles instead of years. If you completely drain your solar battery every single day, it won’t last as long as your neighbor’s battery if they only use half of the energy stored in it daily.
Because of this, most battery manufacturers include cycle warranties or “throughput measurements” on top of their yearly warranty. Most batteries come with between a 5,000 and 10,000-cycle warranty.
Lithium-ion batteries tend to be able to handle more discharge cycles than lead-acid batteries, which is one of the reasons lithium-ion batteries have longer lifespans.
Exposure to extreme temperatures and harsh weather conditions shortens the lifespan of batteries. To help protect their batteries, many homeowners try to install home energy storage in garages or temperature-controlled spaces.
Lead-acid batteries are impacted more by temperature than lithium-ion batteries, adding to the list of reasons lithium-ion batteries have longer lifespans. Lead-acid batteries are typically rated to be stored between 40°F and 80°F, whereas lithium-ion batteries can handle temperatures as low as 0°F and as high as 90°F.
Solar batteries do not last as long as solar panels. Solar batteries have a warrantied lifespan of 10 years, while solar panels are warrantied for 25 years. As we said earlier, the warranty period isn’t the end of the product’s life. So, a battery may last closer to 15 years, and panels could go as long as 30 years.
Regardless, your solar panels will likely outlast your battery. So, you might have to replace your battery before your solar panels to continue using energy storage.
The answer to this depends on many factors, including how much energy the battery can store, how much power it can output, and what appliances you want the battery to run.
In general, most solar batteries won’t be able to power an entire home unless you install a very large and very, very expensive system. However, they can power a few essential appliances, like refrigerators, lights, outlets, and a WiFi router. The following table outlines what a typical 10 kilowatt-hour (kWh) battery would be able to run for 8 hours before needing to be recharged:
Table 1. Essential appliances you can power with a 10 kWh, 5 kW battery for 8 hours
|Essential load||Wattage||Hours||kWh consumed|
|Refrigerator||700 W||8||5.6 kWh|
|Lights||400 W||5||2.0 kWh|
|Electric stove||2,500 W||0.5||1.25 kWh|
|Microwave||900 W||0.25||0.23 kWh|
|Laptop charger||61 W||2||0.12 kWh|
|Phone charger||20 W||4||0.80 kWh|
|Television||77 W||2||0.15 kWh|
|WiFi router||5 W||8||0.4 kWh|
|Total kWh needed||9.47 kWh|
Solar batteries aren’t a suitable investment for everybody. If your utility offers full retail net metering, a battery won’t make very much financial sense because it won’t save you any additional money on your electricity bills. A battery may save you additional money if your utility doesn’t have net metering. However, batteries cost upwards of $10,000, so it probably won’t save you enough extra cash to cover the investment.
The most significant benefit of a battery is that it can power your appliances in a power outage. So, if you live somewhere that experiences frequent blackouts, then a battery could be worthwhile! Ultimately, it’s up to you to decide if the high price tag is worth the peace of mind that your lights will be on when the grid is down.
The best way to see if an energy storage system makes financial sense for you is to use our state-of-the-art solar battery calculator. Not only do we tell you how many batteries you need, but we also give you an estimate of how many solar panels you need and how long it’ll be before you see a return on your investment in a solar panel system.