How Long Do Solar Batteries Last?

The purpose of a solar battery is that it allows you to continue powering your home with renewable solar energy during the evening and at night when the solar panels aren’t able to generate energy.

Although this could be a great new addition to your home, many people are put off these batteries because they do not know how long they last.

Solar batteries can only be used a certain number of times before it reaches the end of its useful life. The key to determining how long it will last is by how often you cycle the battery. Usually a solar battery will last anywhere between 5-15 years.

However there are three factors that will affect the lifespan of a solar battery.

  • The useful life of the battery
  • The battery’s warranty
  • How often you cycle the battery

Useful Life Of A Solar Battery

Useful Life Of A Solar Battery

A solar battery will reach its useful life when it fails to meet its nominated percentage of storage capacity. This is usually around 60%. After this point, the battery will continue to degrade, and it may be able to function at a lower percentage but the batter will have deemed to have reached its useful life.

Solar Battery Degradation

Solar batteries will degrade at a far quicker rate compared to that of solar panels. The best solar panels on the market will be able to perform at 90% effectiveness 25 years into their life span. On the other hand, for solar batteries, the figure is around 60% of its storage capacity after 10 years or when the first conditions of the warranty are met.

Solar Battery Warranties

If you are concerned about the lifespan of a solar battery, then it is good for you to know that most will come with a 10 year warranty. This will be an indication of how long you should expect the solar battery to last.

Despite this, solar battery warranties are not exactly straight forward. Most will come with a number of conditions that will end the warranty before the 10 year period is up.

These conditions are:

  • Warrantied life expires
  • Cycle life allocation is exhausted
  • Energy throughput capacity is reached

Warrantied Life

The warrantied life of a solar battery is the number of years the manufacturer guarantees the performance of the battery. This is usually set at 10 years from the date of installation.

Life Cycles

Some battery manufacturers will include the number of life cycles of the battery as a condition of the warranty. This is a specification that you should look out for, even if it is not included in the warranty. An indicator of the quality of battery is the number of life cycles that it has had.

A singular life cycle of a solar battery is when it fully charges and discharges once.

Depth Of Discharge

Depth of discharge is the level at which the battery can be discharged compared to its normal capacity. As an example, a 9.8 kWh batter with a depth of discharge of 95% will have a usable capacity of 9.3 kWh.

How Often Do You Have To Replace Solar Batteries?

How Often Do You Have To Replace Solar Batteries

The time in which your battery takes to drain, or fully discharge your battery, depends on the size of your battery and how often you use your electricity.

For a typical household that consumes 16 kWh of electricity per day, if we assume two-thirds is consumed when the solar panels are not generating energy, a 10 kWh battery will hold enough enough capacity to store your night time and morning electricity needs. In this instance, it is likely that the solar battery will drain overnight and there fore will need replacing.

How Many Solar Batteries Are Needed To Power A House?

To determine how many solar batteries are needed to power a house, you need to find out how much wattage is needed to run your appliances and lights. After you have done this, you need to run all your appliances and then determine how many hours a day they will run for.

For instance, your refrigerator will be able to run approximately 1/3 of the time during a 24 hour cycle, or 8 hours a day. The light that draws 75 watts may run 3 hours a day. Once you have determined how many watts you use a day from each appliance, add them up to give you the daily watt-hour results.

Are Solar Batteries Worth It In 2021?

Yes is the answer, but it will depend on what you plan to use the solar batteries for.

If you want to be energy dependent then yes, as a solar battery can help to save you a lot of money on energy bills. However do bear in mind that solar batteries are priced between 8 thousand dollars and 12 thousand dollars, so you will need to weigh up if you will make a return on your investment.

On average, a solar battery will help to save a regular household $640 a year.

However, if you want something that will last for an extended period of time and requires less maintenance, then solar panels may be the better option for you.

Final Thoughts

Although they can be very expensive, solar batteries can be a worthy investment into your home.

The solar battery you end up buying and the amount of electricity your house uses will affect how long your solar battery will end up lasting.

It is important to remember before buying that the condition of a solar battery will degrade far quicker than solar panels.

Therefore if you are looking to become more self sustainable, solar panels may be more of a beneficial option.