After considering all the environmental and financial benefits of installing a Solar power system into your house, and after doing all of the research required for you to identify the best solar panel you finally go for installing it in your house. Great!
Now what?
Oh yeah, of course, Battery. One of, if not the most important part of a Solar power system is the solar battery. How could it not be? It is the element that allows you to take benefit of the solar power system at night and at times when Sunlight is not available. But there are many types of Solar Batteries as well. Seeing that, you may find yourself questioning
Exactly how many types of solar batteries are there in Pakistan?
What type of battery should I install for my Solar Power System?
If you also have the same questions in your mind, then worry not, as you have landed on the right page. In this article we will discuss the types of batteries there are in Pakistan, their cons and pros, and which one will be best for you.
Essential Terms Required to Discuss Batteries
If we are going to delve into the technical details of batteries, it would be really handy to know some basic terms used in the realm of batteries. The terms that will be used to discuss the characteristics of the mentioned batteries in this article are:
Depth of Discharge: Depth of Discharge, also written as DOD, is the percentage of the battery that can be discharged without causing permanent damage to the battery. It is important to know DOD of a battery to make effective use of the battery so you can get most use out of it.
Any sort of discharging beyond this percentage will cause your battery life to decrease.
Charge Cycles: One Charge cycle is equal to discharging a battery up to its DOD percentage and then recharging it to the maximum capacity. It is important to consider the maximum number of charge cycles that can be given by the battery, a smart investment will always be to put your money where it will last long.
Self-discharge: Whenever you leave a battery unattended, it loses its juice over time, doesn’t it? Well, this phenomenon is called Self-discharge and also charge retention. A good solar battery must have low rates of self-discharge as there is certainly not any sunlight at night.
Float current: This term is directly related to charge retention rates. Float current is the required low current charging to keep the charge of the battery at a stable level. This required charging is exactly the same as the Self-discharge rate.
Efficiency: Efficiency refers to the amount of solar power that can be stored and used by or from the battery. One should always look for an efficient battery to put in a Solar Power System to ensure that he gets the most out of his purchase.
Types of Batteries
Like any type of technology in the world, batteries are also bound to have a near infinite amount of types. But here you will know about the batteries which will be available to you in Pakistan and the ones you will find easily in the market.
1: Lead Acid Batteries
It would not be wrong to say that the most commonly used batteries are lead acid batteries. They have stuck around for a long period of time because of their reliability. They are cheap and reliable and because they have been around for a long, they are easily recycled as well.
If we talk about Lead Acid Batteries, it wouldn’t be fair to not share the fact that they have further two main types, Flat plate batteries, and Tubular pate batteries.
The scientific difference between these two types of batteries is given below:
“Flat and tubular batteries both are members of the lead-acid battery family. However, in a flat plate battery both positive and negative electrodes of a Flat plate are in shape. But in a tubular battery, negative electrodes are flat plate type and positive electrodes use a frame structure consisting of a series of vertical spines connected to a common bus bar. Each spine is covered by non-conductive tubes filled with a paste of lead oxide active mass.”
1.1: Flat Plate Batteries
Flat Plate Lead Acid batteries are the batteries you would find in cars and other transport vehicles. These are also called normal lead acid batteries. The reason for that is that these machines require a large amount of energy surge in a very small amount of time. This is a job that is nicely performed by these flat plate batteries.
However, if we talk about the cons of this type of battery, there is no doubt that there are some. First of all, this type of battery has a mere average DOD of 50%, meaning that you would want to only use 50% of its capacity before charging it again to ensure good battery life.
Secondly, this type of battery doesn’t have a long cycle. One cycle means the time a battery takes to become fully discharged up to its DOD percentage after being fully charged.
Thirdly, this type of battery does not have many charge cycles either, meaning that you would have to buy one pretty soon. 2 to 2.5 years that is, which seems a lot but really isn’t when we take other types of batteries into consideration.
The fourth con is that these types of batteries don’t have good storage capacity for holding a good amount of charge and even if it does, it doesn’t last long due to higher rates of self-discharge and shorter charge cycles, which also means these type of batteries require a higher level of float current.
The Efficiency of Flat plate batteries is 75% to 80%, which is decent at most.
Lastly, these types of batteries do not support fast charging as they heat up when too much energy is given to them for charging. So, it is easy to conclude that it is a battery best suited to Cars, not Solar Power Systems.
1.2: Tubular Batteries
These are the second type of lead acid batteries and are considered a direct upgrade to the normal lead acid batteries. There are many reasons behind that claim. All of the negative things about the normal type are not present in this one.
Tubular Lead Acid batteries have a longer life span than normal ones, which is on average 3.5 to 5 years. Meaning it has more charge cycles. Due to the tubular plates used in these types of batteries, these are usually taller but have the same width.
These also have longer charge cycles which means they will last longer and be more beneficial for you in days of load shedding. It can also be said that these batteries have a lower rate of self-discharge. Due to lower rates of self-discharge, Tubular batteries also require a low level of float current. Furthermore, these batteries also support fast charging as they do not show any overheating issues. These also have good storage capacity meaning they will hold more charge, this also means it is more efficient, 80% to 85% to be exact. The more the merrier!
Another really cool feature most of the Tubular batteries have is that they have water indicators on top in the place of the normal caps you would find in usual flat plate Lead Acid Batteries. This means you won’t have to regularly open and see the water level yourself.
2: Dry/Gel Batteries
It is a fact that dry batteries or gel batteries aren’t manufactured in Pakistan, and there’s a very good reason for that. Most places in Pakistan do not have the right climate and temperature to keep a dry or gel battery healthy and long-lasting. It is important for these types of batteries that they should be kept nowhere over 25 degrees Celsius. And to keep that kind of battery in the average climate of Pakistan, we would require it to be in a room with an Air Conditioner, but that isn’t possible for all of us, is it?
But if we talk about the pros and cons of Dry or Gel batteries, it wouldn’t be wrong to say that they are very similar to Lead Acid Batteries with the only two differences being that they have a slightly better DOD of 75% (Meaning that 75% of its capacity can be used without affecting its health) and the most famous point of it being that these types of batteries require little to no maintenance, apart from temperature.
Other than that, Gel batteries usually have the same amount of Charge Cycles as lead acid batteries but they are a bit longer due to better DOD. The self-discharge rate isn’t too different either which means so is the float current. Efficiency is also quite the same as Lead acid batteries ranging from 75% to 85%.
Although, shopkeepers do try to scam people by importing such batteries from countries where they work wonderfully and selling them by putting on it the title “Imported”. These are excellent batteries but simply aren’t built for a place like Pakistan, where the temperature changes throughout the year. So these are not so good for your Solar Power System.
3: Lithium Ion Batteries
These types of batteries are new to the market. Lithium Ion Batteries have also gathered attention due to their usage in electric vehicles such as Tesla. These batteries are excellent in every field. Lithium Ion Batteries offer excellent DOD, up to 95% and some even 100%. There is not any shortage of charge cycles either as the average lithium-ion battery can easily give you 2,000 charge cycles. And if maintained well in a suitable climate, 3,000 charge cycles aren’t a problem as well.
The Efficiency of these battery types is absolutely wonderful as well, more than 95% to be exact. Their charge rates are also unmatched and better than Lead Acid Batteries or Dry batteries.
These types of batteries can cost you a heavy amount if you want to buy them and utilize them in your Solar Power System, and that is the only major problem with this battery type.
Characteristics of a Good Battery
What are really the traits that will decide which battery is best for a Solar Power System? After all, what should I look for in a Battery before buying it?
If you have those questions, then here are the answers:
Long Life Span: If someone wants to buy a battery, he should make sure that it is a long time investment and that he would not have to buy one anytime soon.
Fast Charging: A battery should take full advantage of more than one solar panel and of full bright sunshine on a sunny day. If a battery does not support that, then it is possible for it to heat up when faced with such circumstances.
Large Storage: A battery is of little use if it does not last long when you depend on it and only it for power. A good battery should always last you long after being fully charged.
Long life cycles: A cycle is a time taken for a battery to be completely drained out after being fully charged. A battery should also have many cycles, meaning it should take more time for it to be drained out after being charged.
Price: A good battery should always give you the most for the price you pay for it, if not, it would be equivalent to you throwing away your money. Why use your money poorly when you know it can give you more?
Best Battery for Solar Power System:
So, after putting all of the above-mentioned traits of a good battery into consideration, it is easy to say that the best type of battery for your Solar Power System is Tubular Plate Lead Acid Battery.
It is a battery best suited to be used with a Solar Power System due to its long life span, excellent storage, and best of all, Excellent price. Its depth of discharge is excellent for the price range you can get in Pakistani markets. Their long Charge Cycles mean they will help you out in times in need for longer. This is also mainly due to the thick and long Tubular plates found in them.
Overall, lithium Ion Batteries have the best traits but if we consider the prices of all the mentioned batteries, no doubt the best deal is Tubular Batteries.
