How Long Do Solar Batteries Last

Solar Energy Hub may collect a share of sales or other compensation from the links on this page. This comes at no additional cost to you, and all the prices and availability are accurate at the time of publishing.

Solar systems simply cannot function without batteries. They are one of the most important pieces of equipment in any solar setup and choosing the right battery is crucial to getting the most out of your investment. 

Solar batteries come in a variety of shapes, sizes and chemistries, so finding the right one for your needs can be a daunting task. One of the key factors that help you in process of determining which battery is best for you is understanding how long solar do batteries last.

There are a number of factors that will affect the lifespan of your solar battery, including, the type of battery chemistry, the number of cycles the battery can go through, the depth of discharge (DoD), and last but certainly not the least, how well the battery is maintained.

In this article, we will go over all of these factors in detail to help you understand how long your solar battery is likely to last.

How Long Does a Solar Battery Last?

Renogy 12V 100AH Deep Cycle Hybrid Gel Battery, over 750 Cycles, Rechargeable for Solar Wind RV Marine Camping UPS Wheelchair Trolling Motor, Maintenance Free

Solar batteries have a lot of factors that affect how long the battery will last. The type of solar battery, the conditions it is stored in, how often it is used, and how well it is maintained all play a role in its lifespan.

The average solar battery will last between 5 and 15 years with proper care. In its later years, a solar battery will still hold up to 60-80% of its original capacity. Of course, the lifespan of a solar battery can be shortened if it is not properly cared for. If a solar battery is exposed to extreme temperatures, or if it is regularly discharged below 50%, its lifespan will be significantly reduced.

To get the most out of your solar battery, it is important to store it in a cool and dry place and to keep it charged above 50%. With proper care, your solar battery should provide you with years of reliable power.

  • Useful life of a solar battery

This is defined as the number of discharge-charge cycles a battery can support before it drops below a certain capacity threshold. That being said, a battery with a useful life of 1,000 cycles at 80% capacity will only offer 800 cycles when its usable capacity falls to 60%.

  • Warrantied life of a solar battery

A battery’s warrantied life is the period of time during which the manufacturer promises to replace or repair a defective battery, provided it hasn’t been damaged by the user. Most solar batteries come with a warranty of 5 to 15 years.

Like any other product, how long a solar battery lasts depends on how well it is taken care of.

Factors that Affect the Lifespan of the Battery  

The following are some of the most important factors that affect how long a solar battery lasts:

Solar Battery Cycles

The amount of cycles a battery can go through is one of the most important factors in determining its lifespan. A solar battery cycle is defined as a full discharge followed by a full charge.

For example, if you have a 100 amp-hour battery and you discharge it by 50 amps, you would have used up half of its capacity, or “50 amp-hours.” To fully charge the battery, you would need to add 50 amp-hours back into it.

The number of cycles a battery can go through before it needs to be replaced varies by type. Lead-acid batteries, for example, can typically only handle around 500 to 800 cycles. Lithium-ion batteries, on the other hand, can last for thousands of cycles.

Temperature

The temperature of the environment where the solar battery is stored can also affect its lifespan. Extremely cold or hot temperatures can shorten a battery’s useful life. Ideally, you want to store your solar batteries in a cool and dry place.

Depth of Discharge (DoD)

The depth of discharge (DoD) is the percentage of a battery’s capacity that is used up in a single discharge. A battery with a high DoD will be discharged more deeply each time it is used, which can shorten its lifespan.

For example, a 100 amp-hour battery that is discharged by 50 amps will have a DoD of 50%. A battery with a lower DoD, such as 30%, will last longer since it is not being discharged as deeply each time.

Maintenance

Another important factor in determining how long a solar battery lasts is the amount of maintenance it receives. Batteries need to be regularly cleaned and inspected to ensure they are functioning properly.

The terminals should be free of corrosion, and the connections should be tight. Loose connections can cause resistance, which can lead to overheating and shorten the lifespan of the battery. It is also important to keep an eye on the electrolyte level. If the level is too low, it can damage the cells and reduce the capacity of the battery.

Type of Solar Battery

  • Lead-Acid Batteries: These are the most common type of solar batteries and are also the least expensive. Lead-acid batteries typically last between 5 and 10 years. They are made with lead plates and are filled with a sulfuric acid solution. Off-grid energy systems are often employed using lead-acid batteries and they are a good choice for those with a limited budget.
  • Lithium-Ion Batteries: Lithium-ion batteries are more expensive than lead-acid batteries, but they last longer. Lithium-ion batteries can last up to 15 years. The gold standard in solar power is lithium-ion batteries, which are both lightweight and compact. They are made with lithium-ion cells, which are more stable and less likely to leak than lead-acid batteries.
  • Saltwater Batteries: Saltwater batteries are a newer technology. They are made with metal plates and use saltwater as the electrolyte. These batteries don’t contain any heavy metals and are the most environmentally friendly option as are one of the few options that can be recycled, but there is no substantial research on whether these batteries are reliable. 

FAQs

How long do solar batteries hold their charge? 

This depends on a number of factors and is very difficult to estimate. The type of battery, the depth of discharge, temperature, and maintenance all play a role in how long a battery can hold its charge.

However, generally speaking, lead-acid batteries will hold their charge for 5-10 years, while lithium-ion batteries will last up to 15 years that is if they are taken care of properly.

How often do you have to replace solar batteries?

This can vary depending on the type of battery, but lead-acid batteries will typically need to be replaced every 5-10 years and lithium-ion batteries will last up to 15 years. Saltwater batteries, which are a newer technology, have not been extensively tested yet so it is difficult to say how often they need to be replaced.

This can come down to preference but normally if the capacity begins to fall below 40-50% it might be time for a replacement.

How many cycles do a solar battery last?

Different kinds of batteries will have different cycle lives. For example, lead-acid batteries typically have a shorter cycle life than lithium-ion batteries.

The number of cycles also depends on how deeply the battery is discharged each time. A battery that is only discharged by 50% each time will last longer than a battery that is discharged by 80%.

In general, lead-acid batteries will last for 500-1000 cycles, while lithium-ion batteries will last for 3000-5000 cycles. Saltwater batteries, which are a newer technology, have not been extensively tested yet so it is difficult to say how many cycles they will last.

Conclusion 

So, how long do solar batteries last? It really depends on a number of factors, such as the type of battery, how deeply it is discharged each time, temperature, and maintenance. However, in general, lead-acid batteries will last for 5-10 years and lithium-ion batteries will last up to 15 years. Saltwater batteries, which are a newer technology, have not been extensively tested yet so it is difficult to say how long they will last. 

If you take care of your solar batteries and discharge them properly, you can expect them to last for a long time. I hope this article was helpful and thanks for reading!

If you liked this article about how long do solar batteries last, you can check out some of our other articles below —

Leave a Comment