Home » Learn About Solar Lighting » Everything You Need to Know about Solar Lighting Batteries

How Do Solar Batteries Work?

Solar batteries are an efficient way to store energy from the sun and use it when needed. They convert sunlight into electricity, which is then stored in the battery for later use. This process is known as solar photovoltaic (PV) technology.

 

Types of Solar Batteries

Four battery types can pair with solar lighting systems:

• Lithium-ion batteries
• Lead acid batteries
• Flow batteries
• Nickel-based batteries

 

Let’s take a closer look at each type of solar battery, including their benefits and use cases.

 

Lithium-ion batteries

When it comes to energy storage, lithium-ion batteries are relatively new. However, they are becoming increasingly used for solar energy storage after being used in electric vehicles. Lithium-ion batteries are suitable for residential solar installations because they hold more power in a smaller space.

 

Pros:

• Minimal routine maintenance required
• High battery energy density, meaning they can hold more energy in less space than other batteries
• Long lifespan (10 years or longer)

 

Cons:

• More expensive than alternative battery sources
• Slight risk of catching fire due to their chemical composition; however, with proper installation, this risk decreases to almost zero.

 

Lead acid batteries

These batteries have been around since the 19th century and are considered a standard technological device in the solar battery industry. They are particularly useful to use as an emergency backup or for off-grid solar energy systems.

 

Pros:

• Low cost compared to other batteries
• High reliability
• Easy to recycle

 

Cons:

• May require ventilation and maintenance for optimal operation
• Installation limitations
• Need to be charged more frequently than other types of batteries
• Shorter lifespan of 5 – 10 years

 

Flow batteries

These batteries are still emerging in the solar energy storage industry. Their name comes from how they operate. Flow batteries comprise a water-based electrolyte liquid, which flows between two tanks inside the battery.

 

When flow batteries are charged, a chemical reaction occurs inside the battery, allowing energy to be stored and discharged. They must be large, so they are used more frequently in commercial applications than residential ones.

 

Pros:

• 100% depth of discharge, meaning you can completely drain the battery without impacting the battery’s health or future performance.
• Fire retardant liquid eliminates the risk of the battery catching on fire.
• Insanely long lifespan of 30 years.
• Low maintenance.

 

Cons:

• High up-front cost
• Lower storage capacity than other types of batteries
• Low charge rates, so they would need to be large for a commercial solar system.

 

Nickel cadmium batteries

These are among the least popular types of batteries on this list, but they are still an option. In particular, nickel-cadmium batteries are used in the aircraft industry and for other utility solar energy systems.

 

Pros:

• Extremely durable
• Can operate at extreme temperatures
• Low maintenance

 

Cons:

• Toxic – to the point that some countries have banned cadmium altogether
• Difficult to dispose
• Limited ability to hold a charge

 

 

When should you replace solar lighting batteries?

 

Solar lighting batteries

 

Solar lighting batteries are often the forgotten component of solar lighting systems. Yet, they are essential to ensure the lights remain operational and provide reliable illumination.

 

Unfortunately, batteries can fail over time due to a variety of reasons. If you notice your lights are not as bright as they should be, or if they stop working, it may be time to replace your solar lighting batteries, especially if they are at or past their estimated lifespan.

We can help you with all your solar lighting and battery questions. Get in touch with us to learn more.