How Long Do Solar Batteries Last?
Imagine having a solar system installed on your home that you rely on for all your electrical needs, but you have a stretch of overcast days leading to reduced energy output. Many of your appliances run continuously, like your refrigerator and computer, so having a battery backup for solar panels, which stores excess energy your solar system generates, can help keep these appliances running without interruption.
With solar batteries, you’re able to store the energy your system generates for later use, which means you’ll have backup power if the utility grid experiences an outage (if you’re part of a grid) and if you’re off-grid, you’ll be able to have consistent power. Solar batteries are a significant investment, so it’s natural to wonder how long do solar batteries last?
How Long Do Solar Batteries Last?
Typical solar batteries have a lifespan of five to 20 years. Some manufacturers match the lifespan of a modern solar system, promising 30 years. Replacement solar batteries are readily available and easy to install. Due to the high quality of solar batteries nowadays, you may only need to replace them once or twice throughout the lifespan of your solar system.
There are four factors that can affect the battery life, including:
- Charging Times – Charge the battery according to its specifications — type, size, model — to maximize the potential for your battery.
- Maintenance – Follow manufacturer’s instructions for proper care and maintenance. Consider having a professional maintenance service check your battery periodically to ensure it’s running efficiently.
- Temperature – The climate in which you live can affect the lifespan of your battery. If you’re in a location that experiences moderate or mild temperatures, the battery can be installed outside and still perform well. However, if you live in a warmer climate with extreme temperatures, it’s wise to have your battery installed in the basement or garage for optimal performance.
Usage Cycles – The usage cycle refers to the number of times the battery is discharged and recharged. This cycle can have a significant role in ensuring good life expectancy. Most solar batteries are deep-cycle batteries, which can discharge approximately 80 percent of their stored energy before needing to recharge.
Different Types of Solar Batteries
Now that you have a better understanding of how long solar batteries last, it’s time to determine what type of solar battery to invest in. There are four different types of solar batteries currently on the market:
- Lithium-ion batteries
- Lead-acid batteries
- Nickel batteries
- Flow batteries
Lithium-ion batteries are primarily used in solar battery systems and are also used in electric cars, laptops, tablets, cell phones, and other portable devices that are widely available today. These batteries are efficient, compact, lightweight, and have a longer lifespan than other battery types.
How long do lithium batteries last in storage though? These batteries lose their charge (self-discharge) over time even when not in use. In the first 24 hours, they self-discharge five percent and then 0.5-2% per month after. If stored properly, in a cool, temperature-controlled area, away from other batteries and metal objects, they can last approximately three to six years.
Lithium-Ion Solar Battery Banks
Solar battery banks store solar energy for your home and provide backup power when a utility power outage occurs. Companies like Tesla and Generac have brought products like the Powerwall and Power Cell to market as total home battery options for homeowners. Both systems — Generac PWRcell and Tesla Powerwall — use lithium-ion batteries.
Generac PWRcell
Generac, while not a solar company — they don’t have a solar panel or solar shingle — has specialized in backup power for 60 years. The Generac Power Cell, also referred to as the Generac PWRcell, is like other batteries that are on the market currently and even uses the same lithium-ion phosphate technology that Tesla and other solar battery system manufacturers use. The main difference is the way the PWRcell is designed.
The PWRcell is designed to be modular and scalable, unlike other battery options. It has one battery cabinet that can have six individual battery modules inside. This setup allows you to customize your PWRcell based on your home’s specific backup power needs, setting priorities for your PWRcell.
The PWRcell is installed in tandem with a solar system on your home. If you don’t already have a solar system installed, the Generac PWRcell is a good option because it’s all one system, allowing homeowners to have a seamless battery and solar product by utilizing the PWRcell and Generac-branded inverter.
The PWRcell can be installed outside your home or inside a garage or mechanical room. They come with a standard 10-year, 70 percent warranty, meaning after 10 years the battery is guaranteed to still perform at 70 percent of its original performance.
Tesla Powerwall
The Tesla Powerwall is one of the highest density battery storage solutions for residential and light commercial AC (alternate current) battery storage. The Powerwall is different from other battery storage options on the market because it can support larger loads, meaning you can power up more of what you need. The Powerwall can be installed with a new solar system or retrofitted to an existing system. Like the PWRcell, the Powerwall can be installed inside or outside.
This rechargeable lithium-ion battery can maintain a 10 percent reserve so when the power goes out, the battery has enough energy stored to keep a few lights on, keep your freezer from defrosting, and power a few other essential appliances. The Tesla Powerwall lifespan is five years beyond its 10-year warranty.
A single Powerwall has enough energy to cover your emergency circuits, lights, and outlets in the occurrence of a power outage. If you want to power more in your home, like larger appliances or an HVAC unit, two or three Powerwall units would be advised.
Rather speak to a solar professional?
Contact Photon Brothers for a FREE in-home or virtual estimate: (720) 370‑3344 (Colorado) or (805) 351‑3371 (California).
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-acidones do.
- 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.
What are lithium-ion batteries best for?
Lithium-ion batteries are a good choice for residential purposes. These batteries have a better storage capacity and offer longer usage cycles.
Solar batteries have become more accessible and popular in recent times. Even builders and construction companies are focusing more on eco-friendly buildings. Homeowners are slowly converting their homes by opting for solar batteries. Let us look at the factors that determine the lifespan of a solar battery.
The usage cycle is an essential element that determines the lifespan of a solar battery. Since they are deep-cycle batteries, you can recharge them once you have used 80% of the stored energy.
Even the type of battery that you install helps to determine its lifespan. So far, the lithium-ion ones are said to be the best as they last longer and are durable as well. Still, it is always advisable to follow the instructions provided by the manufacturer.
If you live in an area that has mild temperatures, then such batteries are suitable outdoors. The indoor option is for people living in harsh temperatures or extreme temperatures.
Solar batteries do not have maintenance or service issues. But, if you want, you can always get them checked regularly by an expert. Get the batteries checked as soon as you notice any problem for better longevity and use.
It is crucial to figure out the right time when you need to consider charging the batteries. Pay attention to the instructions provided/advised. Do not forget the discharge percentage before recharging the battery. Similarly, overcharging the batteries can affect the battery’s lifespan.
Understanding the payback period of solar batteries
The payback period means the time you take to break even the investment that you made. Generally, the payback period can take around 7 to 13 years, depending on the type of battery you choose. But, there are some other factors as well that determine the payback period. They are as follows
- The size and number of solar batteries installed
- Your energy consumption during the day and night
- Addition of new batteries to cater to your needs
- The kind of appliances or gadgets are linked to the batteries
- How often and duration of power failures in your area.
Important factors to keep in mind while purchasing solar batteries
The various solar battery options in the market can make it very confusing to decide. Many people tend to have a tough time selecting the proper battery because of the choices they have. It is advisable to make an informed decision while investing in solar batteries. Speaking to an expert will help you to understand the type of battery that you should go for. Here are a few critical factors that you should consider.
The brand or company is the first thing that people consider while choosing a battery. Every brand offers a set of perks or benefits when you buy its product. It would be best if you did proper research before deciding which company to opt for.
It is not only the brand but even the battery chemistry that plays an important role. Batteries for residential use are very different from the options for commercial purposes.
Lithium-ion batteries are best for daily use. They are heavy-duty and are a lot sturdier. over, these batteries can withstand various kinds of weather conditions and use.
Pay attention to the average lifespan of the battery before investing. Like all other gadgets even solar batteries have a lifespan before it starts to degrade. It is also best to find out the upgrading and replacement options in case the situation arises.
The consumption needs help to determine how many batteries you would need for your house. If you have high usage, then you would need to install larger-sized batteries. Similarly, if you want your entire home to run on solar power, you need to invest accordingly.
Solar batteries come with different kinds of warranties offered by the manufacturer. Before purchasing solar batteries, be sure to get information on the
- The warranty life offered
- If the company is offering life cycle warranties
- The depth of discharge
- The energy throughput.
Tips to improve the lifespan of the solar batteries
As a user, there are many ways that you can take care of to extend the life of your solar batteries. Small details can make a big difference in many ways. Here are a few tips to help you extend the life of solar batteries.
The environmental temperature where solar batteries are installed makes a difference. Storing the batteries at an optimal temperature will help to maximize the lifespan. It will also help to improve its efficiency.
Under extreme temperature, the solar batteries may either stop working or malfunction. The capacity of solar batteries tends to decrease during extremely low and high temperatures. These fluctuations can hamper and intact the overall lifespan of the battery in the long run. During the winter, store the batteries at proper room temperature.[source 1, source 2]
Extremely low and high states of charge can be stressing the batteries. You need to ensure that you minimize the charging time by considering a partial charge of 80% instead of a full charge. If you decide to go for a full discharge, make sure you take it out as soon as it hits 100%. [source 1, source 2]
To get the most out of the battery, make sure you charge it well. Pay attention to charging time. It is advisable not to use battery desulfation as a way to increase the lifespan of the battery.
Ventilation is another important factor that you can never overlook. Every gadget needs to have proper ventilation to prevent overheating. Even while installing solar batteries, you need to install them in a ventilated space.
Factors that Determine the Lifespan of Your Battery
The lifespan of solar batteries can vary between 5 and 15 years. Of course, this is a very large range, but you have more control over it than you might think.
Several factors play into solar battery lifespan, including what type of solar battery you purchase, how often you use the solar battery, the temperature of the battery or surrounding area, and how well the battery is maintained.
To get the most value out of your solar battery, make sure to learn how various factors affect your battery.
Solar Battery Type
One of the most important and fundamental decisions you can make about the solar battery you purchase is the solar battery type. Depending on the type of solar battery you select, the battery may last longer or shorter in relation to its application. Knowing the pros and cons of each type of solar battery will inform you which applications you should consider them for.
We will be looking at two primary types: lead-acid batteries and lithium-ion batteries. While lithium-ion batteries tend to have many advantages over lead-acid batteries, it’s important to understand how you can use them in order to get the best value.
Lead-Acid Batteries
Lead-acid batteries are generally the least expensive of the two types and the least expensive kind of solar battery overall. The savings on upfront cost make lead-acid batteries an attractive option where budget is a concern. However, lead-acid batteries do come with a few significant limitations.
Lead-acid batteries have a lower depth of discharge, usually referred to as DoD. They also have a shorter lifespan than lithium-ion batteries. However, lead-acid batteries can be an excellent choice for off-grid solar installations that aren’t frequently used.
An off-grid solar installation that isn’t frequently used can get around many of the drawbacks linked with lead-acid batteries. Because of the lower usage rate of lead-acid batteries, you can save a considerable amount of money when designing a power backup system for a boat or RV.
At the end of the day, most lead-acid batteries last between 3 to 5 years but could live as long as 12 years if you take good care of them, Agm battery and Gel battery are the most common sealed lead-acid batteries.
Lithium-Ion Batteries
Lithium-ion batteries are the most trusted for just about any solar system application. They offer a compact, lightweight solution with a higher depth of discharge and superior solar battery lifespan. Adding to their long list of benefits are higher capacities and better efficiency.
All in all, you tend to get more out of lithium-ion batteries versus other solar batteries.
Many lithium-ion batteries will last two to three years, or 300 to 500 cycles, but some can go further. Keep in mind that lithium-ion batteries are best for solar power systems that are actively used. Each cycle of a lithium-ion battery tends to offer more value than a lead-acid battery cycle due to the lithium-ion battery’s higher efficiency, higher depth of discharge, and higher capacity.
How Often You Use the Batteries
When asking yourself, “How long do solar batteries last,” try not to think in terms of years. The best way to measure the lifespan of solar batteries is in cycles.
A cycle is the amount of time it takes to drain and recharge a battery. Cycles are an important detail because you might not always be using your solar battery, or you might be using it constantly. A measurement in years might not do you much good in either case.
With every cycle spent, your battery gets closer and closer to degrading. While degradation happens slowly over the course of the battery’s life, it gets much faster at the end.
egradation affects your battery’s ability to hold a charge. With every cycle, your battery will discharge its charge faster and faster. Once degradation becomes significant, the battery won’t hold a charge long enough for it to be useful.
The best way to extend the lifespan of your solar battery is to pay close attention to your manufacturer’s recommended depth of discharge. The depth of discharge is the charge remaining in your battery, measured as a percentage as you might see in a smartphone.
For instance, if your battery’s manufacturer recommends a DoD of around 40%, avoid draining the battery past the 40% mark. If you fully drain your battery every time, you may significantly reduce your battery’s overall lifespan.
Partial-discharge cycles will help give you the best value. By using only 20% or 30% of your battery’s charge at a time, you can significantly improve its cycle life. For best results, avoid charging your battery to 100%.
Battery Maintenance
fore you ask yourself, “how long do solar batteries last,” you should ask yourself if you’re prepared to tackle battery maintenance. Battery maintenance is one of the most critical factors in determining the lifespan of your battery. Without the right level of care, it’s possible to end up with a dud battery in just a few weeks.
Lithium-ion batteries have the most straightforward maintenance. Every so often, take a State of Charge reading. This will inform you whether your battery is holding a charge properly. Afterward, make sure to check your cables and terminals to verify everything is tight and secure. Finally, dust off your battery so it doesn’t generate any extra heat.
Lead-acid batteries are a little more involved, as there are two types of lead-acid batteries to consider. There are sealed lead-acid batteries and flooded lead-acid batteries.
For sealed lead-acid batteries, all you need to do is check the state of charge with a multimeter occasionally. Do this when the battery is under no load. Then, inspect cables and terminals, and tighten any loose connections. Remember to dust the battery.
For flooded lead-acid batteries, you need to check your battery every two to four weeks for best results. Water levels will drop over time, so make sure to refill using distilled water only. Only fill to the max level line.
Using a refractometer, check the state of charge. You want to see if your battery holds a charge after a full charge cycle. Perform a controlled overcharge every one to three months to ensure your cells are charging equally.
Solar Battery Warranty
Being mindful of a battery’s warranty can help you get more value from your battery. A warranty won’t magically extend the lifespan of a battery, but if something goes wrong, you can rely on your warranty to get a new battery.
Most lead-acid batteries have warranties of five years or fewer. You can expect to see warranties of ten years or more for lithium-ion batteries.
Solar Battery Temperature
Like anything using electricity, temperature is a constantly important consideration. Batteries won’t do well in either extreme heat or extreme cold. The best place for a solar battery is in a temperature-controlled space where it won’t be exposed to the elements.
When exposed to high levels of heat, the chemical reactions inside the battery will accelerate. This will decrease its lifespan and increase the rate of wear and tear, leading to more frequent replacements.
Cold, on the other hand, will slow chemical reactions. This causes electrons to slow down and chemical reactions to end sooner, draining the battery much faster than usual and leading to more frequent drain-recharge cycles.
Lead-acid batteries are especially vulnerable to extreme temperatures. For lead-acid batteries, do your best to keep them in environments where the ambient temperature is between 40°F and 80°F.
For lithium-ion batteries, the range is more generous. Keep them in areas between 0°F and 140°F for best results, and do your best to avoid either end of the temperature spectrum.
How Do I Know If My Solar Battery Is Bad?
Over time, the chances increase that you’ll discover your solar battery has gone bad. Before getting rid of it, do a quick visual inspection. Look for broken terminals, leaking, discoloration, cracks, ruptures, bulges, and bumps.
Broken terminals typically indicate a short-circuit has occurred. If your battery has broken terminals, it is in dangerous condition and should be replaced as soon as possible. Bulging or bumps in the casing indicate overcharging. This usually means there is a problem with the charge controller. If you find any cracks or ruptures, it means the battery has significantly degraded.
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