Solar energy is steering the world towards a more reliable and sustainable source of energy. While solar panels have witnessed a lot of innovations in recent years, now the spotlight is on the role of solar batteries in making solar systems more affordable, efficient, and practical for everyday use.
Solar batteries can significantly boost the overall performance of the solar system. Thus, choosing wisely among them is crucial. Here is a guide to choosing among the 5 types of solar batteries to help you make a wise and more informed decision.
Understanding Solar Batteries
Indeed, solar energy is the most eco-friendly and reliable source of energy. However, it also has some cons associated with it. Among these perspectives, its availability only during daytime is widely discussed.
Solar batteries come into the frame to resolve this issue.
Solar batteries are batteries that store the extra energy produced by the sun. This energy can be used later on in cases of zero to low availability of sun, such as nights, blackouts, and cloudy days.
Talking about the working of solar batteries, these batteries store energy in the form of DC electricity. The sun hits the solar panels, which convert energy into DC electricity, which is stored in these batteries. However, this electricity needs to be converted into AC current again when used.
Types of Solar Batteries
Various types of solar batteries are available around the horizon. Analyzing the pros and cons associated with these types can help you opt for a more compatible battery with your solar systems.
The 5 most common types of solar batteries include:
- Lead Acid
- Lithium-ion
- Nickel Cadmium
- LiFePO4
- Flow
Each of these batteries offers its unique advantages and limitations, details of which are discussed below.
Lead acid Solar batteries
Introduced in the 17th century, lead acid batteries have been serving the energy needs of the masses for a long time. Once the only available type of battery, they have a simple chemistry.
However, with the advancement in battery technologies, they are less efficient than their modern counterparts, like lithium-ion and LiFePO4 batteries.
Their two main types include flooded and sealed lead acid batteries.
Advantages of Lead Acid batteries
- Lead acid batteries are cheap, so they do not put hefty burdens on your pocket.
- They involve deep cycles, which means that they offer constant current flow for long periods.
- These batteries are highly adaptable and can be used within a wide range of temperatures.
- Some lead acid batteries involve gel rather than liquid as an electrolyte, which makes them safer to use in critical applications.
- Last but not least, these batteries are highly recyclable and use around 80% of recycled lead.
Disadvantages of Lead Acid batteries
- Being the forefather of batteries, lead acid batteries are not integrated with modern innovations. This makes them bulky, so they require more space.
- Though recent changes in their manufacturing have increased their life span, this is still shorter than theri modern counterparts.
- Their charging rates are slow, which makes them not very suitable for any fast-paced work.
- These batteries require regular maintenance and, in the long term, could require costly replacements.
Lithium-ion solar batteries
Lithium-ion solar batteries are relevantly new kids in the town of batteries. With numerous benefits that these batteries offer, one that has significantly increased their popularity is their charging capacity.
Still, improvements are under process, and these batteries will soon be a go-to solution for all power storage needs, from EVs to mobiles and home solar systems.
Their chemistry involves the use of lithium ions that move between positive and negative electrodes.
Advantages of Lithium-ion solar batteries
- Space is a fundamental concern when talking about solar systems. Lithium-ion batteries have high storage density. This means they can store thousands of watts without occupying much of your home space.
- Besides their capacity, these batteries also offer a good lifespan that extends between 10-15 years, depending on their usage.
- For solar systems, the charging rate of any battery is crucial as the sun is available for a limited time only. Lithium-ion batteries have a pretty fast charging rate and can be charged within low sunlight periods, too.
- Their discharge rate is around 80%. This means you don’t have to empty much of your battery charging to recharge it.
- Also, lithium-ion batteries do not require any periodic maintenance, which is undoubtedly a cherry on the cake, saving you some bucks.
Disadvantages of Lithium-ion solar batteries
- Safety is the most important consideration when opting for lithium-ion batteries. These batteries, if not handled carefully or punctured, can lead to explosions.
- Next to safety is the price of these batteries. As they involve new technologies, they are costly compared to other solar batteries. However, with advancements in their chemistry, like the use of lithium iron phosphate and lithium cobalt oxide, they will soon be more budget-friendly.
- Temperature is also a coefficient that affects the performance of lithium-ion batteries. In very high and low temperatures, their efficiency decreases to the extent of complete battery damage.
- Another challenge regarding lithium-ion batteries is their recycling process. This is expensive. Also, there are concerns about the mining of nickel and cobalt, the two widely used chemicals in these batteries, posing serious threats to the environment.
Nickel Cadmium solar batteries
Nickel-cadmium batteries are well-known names in the aviation industry; however, their domestic use is limited for some reasons.
Invented in 1899 by Waldemar Junger, these mature batteries have their applications extended from computers to toys and aircraft.
Their chemistry involves the use of nickel hydroxide and cadmium.
Advantages of Nickle cadmium solar batteries
- The most impressive factor of nickel-cadmium batteries is their operational durability in high temperatures. This makes them suitable for use in very hot and cold climates.
- Their lifespan is also admirable. They offer more charging and discharging cycles than their counterparts.
- Next to the life span is the discharge rate of nickel-cadmium batteries. They can provide bursts of high watts, thus considered more reliable in operations where high current rates are required.
- Also, in case of no use, nickel-cadmium batteries have a minimum self-discharge rate. This means they can be used long after being charged.
Disadvantages of Nickle cadmium solar batteries
- Cadmium is a highly toxic metal that can pose serious threats to human health if not disposed of properly.
- Ni-Cd batteries are also vulnerable to memory effects, causing them sudden discharge. This makes their installment questionable in critical operations.
- Lastly, Ni-Cd batteries have been available for a century and do not offer any innovation. Their energy density is comparatively low, which makes them bulky and difficult to move.
LiFePO4 solar batteries
LifePO4 batteries are the modern version of Lithium iron phosphate batteries. Due to the multiple benefits they offer, like their efficiency, lifespan, and safety, they are gaining widespread popularity to be used for solar systems.
Unlike their traditional counterparts that involve lithium, they are cobalt and nickel-free. This, coupled with other fundamental benefits that these batteries offer, makes them a leading light in charging technologies.
Advantages of LiFePO4 solar batteries
- LiFePO4 batteries can operate in a wide range of temperatures. Compared to the temperature range of conventional batteries, which is around 0°C to 45°C, LiFePO4 can operate between -20 °C to 60°C.
- Besides temperature, their energy density is also impressive, which makes them light and a go-to choice for portable electronic devices, EVs, and solar systems.
- The lifespan of LiFePO4 is also greater than its counterparts. It can offer around 2500-5000 cycles and lose only 20% of its original capacity, which is significantly higher than other Li-ion batteries.
- These batteries have very low risks of explosion. This makes them highly suitable to be installed in residential buildings.
- Like nickel-cadmium batteries, their self-discharge rate is also low, but thankfully, they do not come with the toxicity of cadmium.
- LiFePO4 offers fast charging, which makes them valuable options for solar installations.
Disadvantages of LiFePO4 solar batteries
- The initial installation costs of LiFePO4 batteries are comparatively higher. However, talking about their lifespan, energy density, and other benefits, these higher rates are well compensated in the long run.
- Lastly, though LiFePO4 has a high energy density, its energy outputs are low. This means they are not suitable for power appliances with high voltage requirements.
Flow Solar Batteries
Flow batteries or redox batteries are relatively new innovations that are not yet so popular for residential installations. Unlike conventional batteries that rely on metals, they involve the use of negative and positive electrolyte liquids separated by a membrane.
When the current input is provided, chemical reactions occur, resulting in the charging of these batteries.
Advantages of Flow Batteries
- 100% discharge depth without compromising the battery health is the most fundamental advantage of flow batteries.
- Their lifespan is also exceptional, lasting around 30 years, much higher than that of other battery technologies.
- Flow batteries require small to zero maintenance.
- As these batteries involve the use of liquid electrolytes, they are fully recyclable.
Disadvantages of Flow Batteries
- Flow batteries are expensive.
- Their energy density is low. Thus, they are bulky and need sufficient space to be installed.
- Lastly, as they are new in the market, they are not yet available for residential applications.
How to choose the best battery for a solar system
The reasons you are opting for a solar system installation could be diverse. You might be doing it for financial savings or to help you through blackouts or anything else.
But whatever the case is, your solar battery choice depends on your power requirements and how often you are going to use it.
Although the process of buying a solar battery is simple, it has some complexities that demand prudent decision-making. Below are some factors that you should consider before buying a battery for your solar system.
Battery Usage
Determining your energy requirement is the core factor to consider before buying a battery.
The electricity output of a battery is measured in Kilowatt hours (kWh). Now assume you consume 1kWh of energy and you have a battery with 12kWh. It can supply you with uninterrupted power for 12 hours.
Batteries with a capacity of 10kWh or above are usually recommended for home solar setups. However, more batteries could be added later on if your energy demand increases.
Power Rating
The power rating of the battery is the amount of power it can provide at any specific time. In simpler words, it is the electricity that a battery can produce to run a single or multiple appliances.
The usual power rating of conventional batteries lies between 3-5 kWh with a peak rating of 5-7 kWh. The peak power rating is the short burst of energy that any appliance requires when it turns on. However, after that, it requires a low power supply.
Thus, it is important to understand the power ratings of your battery and the appliances you want to operate.
The lifespan
The life span of the battery is another essential factor that helps you make your investment worthwhile.
The lifespan of a battery is measured in three different parameters that are:
- Recharge cycles: This means how many times a battery can be recharged and discharged
- Years of operation: These are years when a battery can offer its services without losing its health.
- Throughput: This is the total amount of electricity that will run through a battery during its lifespan.
Normally, the lifespan of lithium-ion batteries extends between 5 and 15 years, while for lead acid batteries, it is between 5 and 7 years, depending on personal usage.
Type of Battery
The type of battery is the most fundamental point that needs attention prior to buying a solar battery. Multiple battery types are available in the market, and the top 5 among them are discussed above.
All batteries come with some pros and cons. However, talking specifically about solar installation, LiFePO4 batteries are taking the central stage here. They are exceptionally efficient, have longer life spans, good energy density, and recharge cycles.
Furthermore, if you have any specific applications, it's important to select the battery type according to your needs.
Power Losses
Power losses during the electrical process are inevitable. Thus, when solar panels direct electricity toward a battery, it consume some part of it to store and release electricity.
The amount of power a battery consumes to store and release energy is called its Round-Trip efficiency. Batteries with higher Round-Trip efficiency lose less power and thus are more recommended.
Top solar battery recommendations from BLUETTI
In a market stuffed with multiple brands offering their solar battery products, it's hectic to find products that are actually reliable, efficient, and cost-effective. Here, BLUETTI comes into focus with its exceptional product offerings.
Below are the top three solar battery recommendations from BLUETTI that can be your solar system’s ideal pair.
BLUETTI AC500 + B300S
The first on our list is BLUETTI AC500 + B300S. Its feature includes a power rating of 5000W with a surge of 10,000 watts. Its capacity can be expanded from 3072W up to 18432W. The battery type used in this product is LiFePO4. It offers 3500+ life cycles with a battery health of around 80%.
The system is integrated with a smart app control that can be accessed through Wi-Fi and Bluetooth. It has 6 ways recharging options, including AC, solar, generator, lead acid battery, and dual charging.
It supports 99% of your devices with 16 versatile outlets. Lastly, the cherry on the top is the product’s 4-year warranty.
BLUETTI EP500 Solar Power Station
Integrated with a 5100Wh LiFePO4 battery type that offers 3500+ charging cycles with 80% battery health, the BLUETTI EP500 Solar Power Station could be a go-to choice for any home solar installation. This moveable power station has a 2000W pure sine wave output and dual in-grid and flexible UPS modes.
The charisma does not only end here. It supports off-grid energy storage, supporting multiple devices simultaneously.
Furthermore, the addition of new techs like a touchscreen and accessibility through a mobile app definitely makes this product one of the best.
BLUETTI EP800 + B500 Home Battery Backup
The last of our pick-ups is the BLUETTI EP800 + B500 Home Battery Backup. The product offers a staggering 7600W continuous power output with dual 120V/240V voltage options. This home battery backup supports solar input of up to 9000W with an exceptional 10-year warranty.
It is compatible with all new and existing solar systems. Furthermore, integrated with the best LiFePO4 battery type, the safety of the system is exceptional.
The Bottom Line
There is a wide range of battery options available on the horizon. One could be best for domestic solar installations, and the other could best support professional operations. However, one thing that requires the utmost attention is the personal and environmental safety.
Where metals like cadmium and cobalt are posing a huge risk to the environment and individuals, batteries with LiFePO4 could be the best way forward.
