How Long Do Solar Batteries Last?
Not all solar batteries are created equal, so the life expectancy varies greatly.
Lower-end lead-acid batteries may only last about 3-5 years. However, if you opt for premium lithium-ion batteries (such as Tesla Powerwall, LG Chem RESU, or Enphase Encharge), they will probably last a good 10-15 years.
To help you understand why some batteries last longer than others, we’ll take a look at some key factors that impact life expectancy, including:
- Lead-acid vs. lithium-ion technology
- Depth of discharge
- Battery storage environment
Battery storage can be a complicated subject, but the Photon Brothers team makes it simple and easy to navigate. When you speak with our licensed solar professionals, we’ll review all of your solar panel and battery options, including which ones will work best for your lifestyle and budget.
Lead-acid vs. lithium-ion technology
Lithium-ion batteries last significantly longer than lead-acid ones do.
But why is that?
A few reasons:
- Lithium-ion batteries offer greater storage capacity. This means they can disperse more energy for consumption— and for longer periods of time— without being drained. We’ll discuss more on drainage below, but it’s important to know that it poses a big threat to your battery’s lifespan. If you use up too much energy, for too many times in a row, you risk draining your battery beyond the point of no return. Unfortunately, this is a common occurrence for lead-acid batteries. While much less expensive to purchase and install, homeowners frequently report having to replace them (due to overuse) after just a few years.
- Lithium-ion batteries are more energy-efficient. All batteries will decrease in efficiency over time, but because lithium-ion batteries average about 15% higher efficiency than lead-acid ones, you’ll enjoy longer (and more effective) use.
- Lithium-ion batteries charge faster. Unlike lead-acid batteries, lithium-ion batteries can charge relatively fast. The reason this plays into lifespan is because you won’t risk draining your battery before it has a chance to recharge. As we mentioned above, frequent drainage can cut a battery’s life short.
Depth of discharge
In the solar industry, battery drainage is referred to as “depth of discharge.” Meaning, the amount of energy that can be safely consumed without harming the battery’s charging capabilities.
If you frequently use more than the depth of discharge allowance, you risk burning out your battery completely. Then it won’t matter how old your battery is, its lifespan is over.
As a rule of thumb, lead-acid batteries shouldn’t be drained beyond 50% of their capacity. Comparatively, you can use up to 85% of a lithium-ion battery’s energy bank before its considered unsafe.
Depending on your energy needs (related to your climate or solar panel setup) you may require greater battery storage. To avoid depleting them through overuse, it pays to invest in premium batteries that offer a higher depth of discharge rate.
Battery storage environment
Solar batteries can take up a fair amount of space. If you fail to store yours in a safe environment, you risk limiting their lifespan.
For example, extreme temperatures can put strain on your batteries, causing them to drain more quickly. And if exposed to rain or water pooling, your batteries could begin to leak and then die completely.
Currently, Tesla’s weather-permitting guidelines state that Powerwalls will lose efficiency at negative 4 degrees Fahrenheit. So if temperatures drop into the negatives in your area, you may want to install yours inside the garage or in a dedicated shed or solar cabinet.
Solar cabinets can cost a few thousand dollars, but when you consider the cost of your solar battery investment, it’s well worth the protection!
Note: Some batteries cannot be installed at higher elevations. If you live above 7,500 feet, speak with a solar professional to learn about your solar battery options.
Certain kinds of lead-acid batteries need maintenance every few months. If you don’t keep up, your batteries won’t last as long.
For example, flooded lead-acid batteries need to be regularly topped off with distilled water in order to operate. It’s also important to clean the battery terminals, otherwise you risk corrosion buildup.
If you’re a busy household— or you simply don’t want the stress of maintaining solar batteries— you might consider lithium-ion batteries. They require almost zero maintenance!
Want a FREE solar battery estimate?
Contact Photon Brothers today! During your free in-home or virtual consultation, one of our NABCEP-certified solar experts will provide you with honest and customized energy storage recommendations. We offer the most advanced solar batteries on the market, all backed by industry-leading warranties and a guarantee of 100% customer satisfaction.