Flooded Lead Acid Batteries for a Home Solar System?

I have recently been on the hunt for equipment for a home solar system. Power shortages where I live are now such that I need to wake up in the middle of the night to do freelancing work. That is hardly sustainable in the long run. Anyway, I have carried out so much research on the components that are needed in an off-grid system that I am probably an expert by now. So, should you choose flooded lead acid batteries for your home solar system?

Available types of solar battery

Before answering that question, it’s worth pointing out that there are five main types of battery that are used in off-grid solar energy systems. These are;

• Flooded lead acid
• Sealed lead acid
• Gel
• Amalgamated Glass Matte (AGM)
• Lithium ion

Flooded lead acid batteries

Flooded batteries have been around since the invention of batteries. However, they have, over the years, acquired something of a bad reputation. That has nothing to do with their performance; they are still one of the best types of battery that can be found out there. Rather, the bad repute has to do with the fact that other; seemingly better technologies have come along. All the other types are sealed and maintenance free, making it sound as if maintaining a flooded lead acid battery is a chore. However, that is hardly the case.

Why are they called flooded?

Flooded lead acid batteries are flooded because they have a liquid electrolyte. And therein lies the problem, in some people’s eyes. The electrolyte evaporates during the process of charging and discharging your solar battery. As a result, it needs to be periodically topped up. However, don’t let that scare you. On most of the types of flooded lead acid batteries that are out there, you don’t actually need to top up the electrolyte for months at a time.

Advantages of flooded lead acid batteries

The following are some of the advantages of flooded lead acid batteries;

• They have been around for a long time and are tried and tested technology.
• They are the cheapest type of battery that you will be able to find on the market today.
• They are relatively robust. Unlike Gel batteries, as an example, flooded lead acid batteries are not prone to being damaged due to overcharging.

Disadvantages of flooded lead acid batteries

Flooded batteries do have the following disadvantages, however;

• They are flooded and there is always a danger that the electrolyte will spill.
• The electrolyte needs to be periodically checked and topped up.
• They emit emissions during the charging and discharging process. These emissions can be harmful. It’s, therefore, not advisable to put this type of battery in a place where people live.
• They have a shallower Depth of Discharge when compared to other types of battery. Discharging them beyond 50% DoD is a recipe for disaster.

Should buy flooded lead acid batteries for my system?

The reason why I ended up writing this article is because I got into one of the reputable solar shops in Harare and they have various types of battery. The salesman there tried to steer me towards sealed lead acid and AGM batteries in the shop. However, my eyes were caught by these huge flooded lead acid batteries on the other side of the shop. Now, that’s a big battery!

They are what is referred to as tubular lead acid batteries. They are designed in such a way that you can see the level of the electrolyte, which is great. However, the one in that shop only had 150ah, which was not great considering their size.

You need ventilation

It later turned out that the batteries are made India, where they are a very popular type. They also last twice as long as normal lead acid batteries. Anyway, I will consider buying flooded lead acid batteries for my solar system. You only need to make sure that there is enough ventilation where you keep them. 

That’s because the one major disadvantage of flooded batteries is that they cannot be placed in a room where people live. They produce dangerous gases, and you want to put them at a place where there is enough ventilation. So, if you have an extra room somewhere where you can put them, flooded batteries are a great choice for a home solar system. They are cheaper and are tried and tested technology.