Depending on the type, solar batteries have a lifespan of 5-25 years with an estimated number of cycles they can go through before losing capacity. Lithium-ion batteries typically have longer lifespans than other solar battery types (lead-acid, flow, etc.) and a 10-year warranty.
Homeowners with solar panels sometimes install solar battery storage systems for backup power. Solar batteries store energy produced by the panels during the day so that it can be used at night or when there is a power outage in the case of grid-tied systems. For off-grid systems, batteries are an essential part of the solar installation.
Since solar storage is expensive, it’s common for homeowner to ask how long solar batteries last. The answer is, it depends on many factors, but in general solar batteries can last 5-25 years depending on the type and usage.
What Affects The Lifespan Of A Solar Battery?
Factors that impact the longevity of a solar battery are battery type, quality, depth of discharge, charging and discharging rates, temperature management, and general maintenance.
Battery chemistry/composition (battery type)
Four standard types of solar batteries are lead-acid, lithium-ion, flow, and sodium nickel chloride batteries. There are subtypes as well, like lithium polymer and lithium iron phosphate, both lithium-ion. Alternatives include nickel cadmium (NiCad), sealed lead-acid batteries, and saltwater batteries (powered by saltwater electrolytes).
Lithium-ion batteries have the best life expectancy, while lead-acid ones have a shorter lifespan.
Some battery manufacturers make better, longer-lasting home batteries than others, so do your research before deciding on a brand. Besides using batter materials, high-quality batteries undergo multiple testing processes in the manufacturing phase. Plus, they tend to have better specifications in terms of voltage stability and self-discharge rates.
Depth of discharge (DoD)
The depth of discharge is the usage cycle measured in percentages. Lead-acid batteries typically have a DoD of 50%, while lithium-ion solar batteries range from 70% to 80%. If a battery’s DoD is higher than 80%, it’s called a deep-cycle solar battery. To prolong the battery’s lifespan, do not use all of its capacity before recharging it, and avoid overcharging.
Charging and discharging rates
Higher charging and discharging rates than recommended will affect the solar battery storage lifespan. Recommended rates depend on the battery manufacturers, so check your manual for specifics. Generally, they range from 40% to 80% percent.
Extreme temperatures (both too hot and too cold) can reduce your solar battery’s capacity performance and life expectancy. 77°F is the ideal temperature for most, and the optimal operating range is from 50°F to 85°F.
Although there are hermetically sealed maintenance-free solar batteries, most require some level of basic maintenance. This typically involves monitoring and cleaning the battery.
How To Extend The Lifespan Of A Solar Battery
You can do the following things to prolong your solar battery storage lifespan: install the proper size, monitor and clean it when needed, and manage the temperature.
Install the proper size for your energy usage
The right battery size mainly depends on two factors: your daily energy consumption and the DoD. Look at your electricity bill and divide it by the number of days in a given month. You’ll get the result measured in kilowatt-hours (kWh). Then, multiply it by the autonomy days (the number of days you’ll get solar power without direct sunlight) and divide the result by the depth of discharge.
If that sounds confusing, don’t worry, a reputable solar installation company will be able to recommend the correct size battery.
Regular maintenance, inspection, and cleaning
Regularly checking the charge level of your battery is the best way to discover any fault in the system. Lead-acid batteries may need routine checkups more regularly than lithium-ion ones.
If you have a lead-acid battery, keep in mind the acid can leak and the hydrogen inside the battery is flammable. Keep yourself safe by wearing protective glasses and gloves. The cleaning part is the same for all battery types — simply remove accumulated dust or dirt from the battery and its terminal.
Install a smart energy management and monitoring system
You can track changes in real-time by getting a Smart Energy Management (SEM) system. The monitoring system will help you maximize your battery’s performance and lifespan by automating several processes:
- Performance data monitoring (including continuous charge level checkups)
- Charging and discharging optimization
- Solar power system integration (smart monitoring can be fully integrated with other home solar system components)
- Energy pattern analysis
SEM systems are remotely controlled, meaning you can adjust them even when you are away from home.
To avoid damage due to extreme temperature changes, make sure to ventilate the room where your batteries are stored for better airflow. Alternatively, use a heat sink to protect the battery. When it’s too cold, use insulation or a battery heater.
Frequently Asked Questions About Solar Battery Lifespan
Are there any drawbacks to storing solar energy in batteries?
The main disadvantages of these energy storage systems are the high upfront price of installation, safety concerns, and limited capacity.
How much power can a solar battery store?
A single solar battery can store anywhere between 1 kWh and 10 kWh. Batteries can be combined for a stronger home energy storage system.
Can a lithium battery last 20 years?
While it’s possible for a lithium-ion battery to last 20 years or longer, solar batteries generally last about 10 years, which is also their standard warranty.
How long will a 10kw battery power a home?
The estimate for a 10kw solar battery is about 10 to 12 hours for an average American household consuming 1,000 watts per hour.
What’s the longest-lasting solar battery?
Lithium-ion solar batteries last longer than other battery types. They are also considered superior to traditional lead-acid batteries.
Does a battery lose its charge over time?
Like any type of battery, solar battery systems gradually lose their charge over time.
How much does a solar battery cost?
The cost of a solar battery depends on the solar energy storage system size and the battery storage capacity. It ranges from $3,000 to over $20,000.