Different Types of Solar Batteries: Which one to use?

Solar power is an excellent renewable energy source that can take us one step further to a green Earth. Knowing your Solar power system in detail can help you fulfill your requirements. That one thing that makes your solar system self-sufficient under any condition is the Solar Battery.

As in the name, it works as an energy source. When your solar panels cannot produce power due to a cloudy sky or at times after sunset, you can run your house or workplace with the energy stored in the battery.

Solar Panels produce DC power by the PV cells (photovoltaic panels), and it absorbs the sunlight and generates electric power.

Now, what if it’s a sunny summer day when your panels are getting too much sunlight and keep on generating power!

They will produce much more energy than you need. That ‘excess energy’ is stored in the Solar Batteries for future use. As soon as you realize that you’re using green energy for your living and also not wasting any of it, you start to admire your Solar System truly. Don’t you? 

Solar batteries are an essential part of your green living journey. 

Here are some points we have to keep in mind. Solar batteries are fundamental elements of your solar system if you have an off-grid or hybrid system.

After knowing the beneficial aspects of solar batteries, you will accept that it is essential for any type of solar system! 

Still, if you have a grid-tied or on-grid system, you are good to go without a battery. But at your own risk. Because the power station gets down, the electric supply to your home or workplace is shut. 

So, having a solar battery is always beneficial for you, whatever your system is. 

In this article, I’ll help you know about different types of solar batteries, their use, cost, and all you need to care about. Read till the end to know about the best fit for your solar system. 

What Makes a Good Solar Battery? 

At first, we may think about how solar batteries work? Well, here’s what we need to understand first! The goal of a perfect solar battery is to store excess energy produced by the solar panels (photovoltaic cells).

There are multiple solar batteries with different chemical properties, but the sole purpose is invariant. In this blog, you’ll learn about each type in detail. Apart from the chemical functionality of a solar battery, all operate similarly in the solar system. The photovoltaic

cells produce DC power entrapping sun rays stored in the battery if not used or in excess.  

Now we are coming to the main topic, for an excellent solar battery, you’ve to watch some factors like Capacity Rating and Power Rating.

Capacity Rating tells us how much power a solar battery can store, and Power Rating gives us the idea of how much power it can deliver to our house at once. It would be best if you also considered the lifespan, safety rating, least hazardous, and last but not least, cost-efficiency of a solar battery.

All these factors together make a perfect Solar battery. Manufacturers have developed different solar batteries to fulfill your various needs and demands.

Know the Best Battery to Pair your System

Finding the befitting Solar battery for your system is not so hard. But at first, it may seem a little confusing because of the large variety out there.

You have to understand your needs first. As soon as you know how you will use your solar power system, you can choose a battery to get the most out of your solar system.

You have to consider certain factors. You have to consider the battery size according to your installation area. Also, a quick and easy installation procedure will be excellent.

Maintenance of the battery regularly can be hectic, and you must consider a battery with low maintenance and high precision. 

If you go online and search on your browser, you’ll find many types of solar batteries available in the market. But while buying one for your system, you have to know which one suits your purpose seemingly.

For that, you need to know about the different types of solar batteries. Also, you’ll not need a solar battery at all in some cases! Though nowadays solar batteries are pretty affordable, they are indeed somewhat expensive!

Different types of Solar Batteries

Among the different types of Solar Batteries, four major types are Lithium-ion, lead-acid, nickel-cadmium, and flow batteries. All of them are specifically designed to serve some specific purposes. 

1. Lithium-ion batteries:

Most used Solar batteries are lithium-ion batteries. They last almost 12 years and don’t get damaged easily.

There are mainly two types of lithium-ion batteries:

1) Nickel manganese cobalt (NMC), 2) Lithium iron phosphate (LFP). NMC batteries can hold more electricity in smaller areas and are common in the market nowadays. In contrast, LFP batteries have a longer lifespan. 

• Advantages: Higher DoD, compact size, no regular maintenance needed, longer lifespan, holds more energy over a period of time.
• Disadvantages: Expensive, Hard to recycle, chances of catching fire.

 2. Lead-acid batteries:

The most cost-efficient option in solar batteries is Lead-acid batteries. The most crucial thing to keep in mind in the case of lead-acid batteries is that these batteries are nearly maintenance-free. Once you install it, there’s no need to worry about its maintenance over the years. 

Two main types of Lead-acid Batteries are Flooded lead-acid and Sealed lead-acid batteries. Sealed lead-acid batteries such as AGM and gel batteries efficiently provide sufficient power backup at a low price. 

• Advantages: Cheap, easy to recycle
• Disadvantages: Shorter lifespan, low DoD, flooded lead-acid batteries need regular maintenance. 

3. Flow batteries:

These types of batteries are a kind of new technology. These batteries have electrolyte liquid that flows between two tanks or chambers inside the battery.

Flow batteries are expensive and harder to maintain in the long term. They require a considerable amount of maintenance over time, but these batteries are easy to recycle. The lifespan of a flow battery is typically around ten years. 

• Advantages: The main advantage of flow batteries is that they don’t lose charge, 100% DoD (Depth of Discharge).
• Disadvantages: High maintenance, expensive, large size

4. Tubular battery:

Tubular batteries are special lead-acid batteries. These batteries are large and usually used in places suffering from frequent blackouts or long power cuts. We measure the battery capacity in Ampere hours.

• Advantages: Better discharge rate (C10), low maintenance.
• Disadvantages: Heavy, requires more space to install.

5. Nickel-cadmium batteries:

Ni-Cd Batteries are not widely used, although they have some fanbase in the aircraft industry. These batteries are remembered for large-scale usage. But if saying specifically Ni-Cd Batteries are not particularly designed for PV systems. 

• Advantages: Can operate in extreme temperatures, maintenance-free, durable.
• Disadvantages: Chemically hazardous due to toxic cadmium, not good at holding charge.

Cheapest and Most Expensive Batteries in the Market

Good news for you! The more houses install solar batteries, their prices decrease. 

But the most expensive solar battery can cost up to $25,000, including installation, whereas typically, it costs between $7000 to $17,000 to install a solar battery in your system. 

Well, I don’t have to mention that battery prices keep changing depending upon which country you are in and the battery’s capacity. 

In the USA, many places are under Government programs that help to nullify the cost of setting up a solar system as much as possible, including battery installation. 

The total installation price is always reasonable to know, but if you want to compare the prices of two batteries, you need to look at the cost per kWh. This cost per kWh is what you have to pay for each kWh of electricity getting stored in the battery.

Just in case, the total cost of two batteries can lead you to the wrong conclusion. Let one battery cost you $15,000 with installation, and another one costs $17,000. In general, every one of us will conclude that the first one is our shot.

But if you think twice and look at the cost per kWh, the story may reverse. If the price per kWh is around $700 for the first battery and $600 for the second battery, choosing the second battery will be far better because you have to pay less per kWh of storage. This will help you reduce a high costs in the long run.

Apart from all this, if you solely look at the installation cost of a solar battery, it may seem a bit high sometimes. But it’s worth it. Look beyond just the cost.

Once you install your own solar batteries and your solar system, you don’t need to worry about bills anymore. You can use environmentally friendly electricity that leaves zero carbon footprint! Seems convincing, right? 

Final Thoughts on What is Best for You

Before concluding which solar battery will be best for you, we have to examine the following factors keenly:

1. Power Rating: This particular feature helps you ensure how many appliances you can use at once. Power Rating measures the amount of electricity delivered to your home at any time, measured in KiloWatts (kW).

Usually, solar batteries have two types of Power ratings: Peak Power Rating and Continuous Power Rating. Peak Power Rating is the amount of energy a battery can release at any time.

This type of energy boost is needed for some appliances at our home for a thrust to start. However, the Continuous Power Rating shows us how much power the battery can give to us continuously.

This is hugely effective when running a desktop, refrigerator, or any other electronic gadget that needs a constant stable power supply. 

Hence, you have to pick a battery with suitable power ratings depending upon your usage. 

2. Capacity Rating: Capacity Rating is the value of the total energy that your battery can store, and it is measured in Ampere hour(Ah) or Kilowatt-hour (kWh).

A standard solar battery should have a capacity rating of at least 10kWh, and it determines how long your battery can supply electricity to your house. 

While buying a battery looking at the Capacity Rating alone can not do good for you. Checking the capacity and Power Rating together can give you an optimally functioning solar battery.

Some of you need an uninterrupted power supply for a long time, and some of you need to run multiple appliances simultaneously. If you need a constant supply over a period of time, then a battery with a low power rating but with high capacity can serve you best.

But if you need to run multiple appliances simultaneously, then low capacity batteries with high Power Ratings should be your choice.

3. Depth of Discharge: Depth of Discharge or DoD is nothing but the value of how much energy can be used from your solar battery before recharging it.

Solar batteries need some amount of energy left in them for proper functioning. If your manufacturer claims a DoD of 80%, you can use 8kWh out of 10kWh of total stored energy.

Keeping track of DoD can help you with optimal battery performance. Before buying your solar battery, don’t forget to check for higher DoD. 

4. Lifespan: Traditionally, Solar batteries have a lifespan of at least 10-12 years. Manufacturers provide a warranty in terms of charging and discharging cycles, and this gives us an idea of how long a solar battery will function properly. Ensure to buy your solar battery that comes with the best warranty.

5. Battery type: Many solar batteries are available in the market. Each of them has some specific advantages and disadvantages too.

Manufacturers have so far designed all types of batteries to fulfill your particular need. You have to choose wisely which type of solar battery is the most compatible with your solar system. 

6. Round-trip efficiency: Suppose your battery stores 12 kWh and gives 10kWh back. Then the Round Trip Efficiency of your solar battery is 83.33% which means 10kWh/12kWh.

So, you see Round Trip Efficiency of a Solar battery is given by the ratio of the amount of energy delivered by your solar battery to the energy stored in it. If your battery has high Round Trip Efficiency, you can use more of the produced electricity, which will help you save a handsome amount of money.

Hence, you can tell yourself that a solar battery with high Round Trip Efficiency will benefit your solar system.

7. Safety Rating: As we intend to install solar batteries for your home or workspace, we need to be cautious. After all, batteries are made of chemicals.

But I can assure you here. Solar battery manufacturers have done a great job, and these batteries are very safe to install. But some batteries are sensitive to extreme temperatures, and you have to consider the climate while buying a solar battery.

Core factors to Remember 

I’m sure you’ve got enough information about different types of Solar Batteries and how they differ from one another. You’ve also got an idea of what will be an optimal choice for you.

If all this streamlining of information together messed you up, look upon the following core factors that you’ve to take away before leaving this page! 

• Always consider and compare the cost of your solar battery before purchasing.
• The two most important factors that you should never miss checking on are the Power Rating and the Capacity Rating of your Solar Battery. 
• If you intend to run multiple appliances simultaneously, a battery with a high Power Rating is your go.
• If you wish to power your house for a longer time gap, you should consider buying a battery with a high Capacity Rating. 
• Always go for a deep-cycle solar battery. Usually, solar batteries are deep cycle batteries, but it’s better to cross-check. 
• Depth of Discharge or DoD is the measurement of how much energy you should leave in the battery to ensure it doesn’t get damaged. This is a critical rating that you must check before buying a solar battery.
• Want maximum saving while using your Solar Batteries? A battery with high Round Trip Efficiency can help you with that. 
• The battery’s nominal capacity is the next thing you have to check according to your need. It is the amount of total energy a battery can store. 
• Buy your solar battery after ensuring that the manufacturer and Installer provide proper installation and post-installation support. 
• If cost is not an issue and safety is the first thing for you, then Lithium iron phosphate (LEP) batteries are your thing. 
• If you have a space crunch, then a lead-acid or an NMC (Nickel manganese cobalt) battery will be a good choice for you. 
• Once you buy a solar battery, it will be a pretty investment. Make sure your battery has a minimum of 10 years warranty and needs minimum maintenance in the longer run.