How do you tell if a battery is sealed, GEL, or flooded?

People all over the world are directly or indirectly using batteries one way or the other. But, do we know about the types of batteries and identify the current condition they are in? 

How do you tell if a battery is sealed, GEL, or flooded

How do you tell if a battery is sealed, GEL, or flooded :Step by step guide

How do you tell if a battery is sealed, GEL, or flooded

Truth be told, it’s difficult to identify a battery’s type just by looking at it once. Trust me when I tell you: It’s easy to fall for it and make the wrong purchase when it counts. So, how do you tell if a battery is sealed, GEL, or flooded?

The first and foremost thing to do here is to know what battery you’re working with. In simpler terms, “Know the specifications of the thing you’re working with.” 

Knowing about their features along with pros and cons helps. And you’ll also need to understand the key points when comparing each battery. 

The way you handle each type is different. Do it wrong and it can ruin itself and the surroundings too. 

Don’t worry, In this article… I’ll tell you all there’s to know about batteries and their conditions. After that, it’s the matter of picking the right one for the right kind of job. 

What is a “Sealed” battery? 

What is a “Sealed” battery

Sealed batteries come with electrolyte inside. This kind of battery is sealed against the spilling of electrolyte. Hence, the name. “Sealed” batteries are modified versions of “Flooded” ones. The inside part of these products are largely the same. A layman won’t be able to tell the difference.  

This kind of battery arrives with a sufficient amount of acid. The acid has a definite purpose. It helps in sustaining chemical reactions. These things are widely used for deep cycling. Sealed batteries are crucial when it comes to kickstarting engines. All modern automotive batteries are sealed ones. 

Unique Features These Batteries Have

  • The trick lies in maintenance of these items. We don’t need to run any! Got you there, didn’t I? 
  • Sealed batteries are spill-proof. I can take it anywhere I like. Safely, I must add. No, there won’t be any trouble (think igniting flammable objects) or spoiling other parts.
  • Usually, a sealed battery can last more than 12 years. The duration is dependent on the manufacturing quality, heavy usage, and so on. 
  • These batteries won’t leak. That’s why you can handle these on the surface or air without maintaining special precautions. 
  • Considering the fact that we use our cars “Almost” daily, these batteries provide us value for money.
  • The sealed battery comes with design flexibility. And it makes the sealed battery versatile for both cyclic and standby applications. 
  • A high discharge rate is one of the most important factors while evaluating a battery. It happens because of the low internal resistance of the sealed battery.
  • All the sealed batteries have a wide operating temperature. They discharge over a range of -4 degrees Fahrenheit to 140 degrees Fahrenheit.
What is a “Sealed” battery


  • No additional maintenance.
  • Special engineered function to prevent the splitting of the electrolyte.
  • Lasts for a long time.
  • Operates without any trouble in critical weather.
  • The convenient design makes it versatile for multiple purposes.


  • If the acid gets out of the protection, it can harm human skin.
  • Highly sensible when there is any fire or flame. 
  • Too heavy to carry.

What is a GEL battery?

What is a GEL battery

GEL batteries come with silica or sand inside of them. It makes the acid of the battery thick for holding the electrolytes together. Despite the suspended electrolyte, a GEL battery is considered similar to the AGM battery. But, the cell of a GEL battery isn’t wet like the AGM one. Like a sealed battery, a GEL battery arrives with a maintenance-free feature. 

A GEL battery isn’t manufactured for wide use. It’s highly used in deep discharge situations. A GEL battery is used as a medical mobility battery, RV deep cycling battery, and so on. However, a GEL battery lasts up to six years after the first use. A good one can also work for almost ten years. This battery is worthy because an optimized performance will be found throughout its lifespan. 


  • GEL batteries provide the current energy of 1A. 
  • Its operating voltage is 12 volts. That’s a good parameter for battery performance.
  • A GEL battery is maintenance-free. No necessity for remembering any special precaution while using for general purposes. 
  • A GEL battery is usually manufactured from 8.2 kg weight. Depending on its capacity, it can range from 8.2-52 kg.
  • It’s possible to last a GEL battery for around 10 years. This lifespan depends on the heavy usage and the purpose of the use. 
  • An average of 20% charge of a GEL battery discharges when it’s out of use. This percentage is applicable for one-year calculations. 
  • About 400 discharges are possible by a GEL battery. So, anyone can highly rely on it. 
  • It’s efficient with its low internal resistance.
What is a GEL battery


  • Gets operated at an optimum voltage.
  • Maintenance-free, no additional safety alert.
  • The smaller versions are easy to transport.
  • Lower discharge rate with developed efficiency.
  • Doesn’t lose its capacity even after a 1-year idle period. 


  • Strict monitoring is required for the supplied voltage.
  • Sensitive than other batteries in critical temperatures. 
  • It’s slightly costly in comparison to the overview. 

What is a flooded battery?

What is a flooded battery

Have you ever heard of the popular Daniell’s battery? If the answer is positive, then you’ve seen something close to the flooded battery. A flooded battery is almost close to Daniell’s battery according to the design. There is the presence of water along with sulfuric acid inside of a flooded battery. Anyone can feel the movement of the liquid inside a flooded battery. 

This battery has a special use in conventional automotive starting, deep cycling, and many more. In addition, this battery is compatible with solar and emergency backup systems. The users can add some distilled water to prevent a flooded battery from drying. If it’s about the last-longing, flooded batteries last longer than the sealed batteries. 


  • Flooded batteries come with its liquid electrolyte. The presence of water with sulfuric acid makes the cell of a flooded battery effective.
  • Almost 2.1 volts are produced per cell of the flooded battery. This output is okay for all the flooded battery purposes.
  • A flooded battery comes with different voltages for versatile purposes. Commonly, it is found with 12 volts but 6 volts for the older equipment. For aircraft starting applications, the value is 24 volt. 
  • The battery cell gets tried after a certain time. So, the user needs to apply some distilled water to run this battery successfully. This task makes the battery a high-maintenance battery. 
  • A flooded battery is highly sensitive in extreme weather. The cold weather can freeze the water inside the battery. And the performance of the battery turns off immediately. 
  • Typically, a flooded battery lasts around 3-5 years. 
What is a flooded battery


  • Highly reliable under the optimum temperature.
  • Long deep discharge cycle life makes it selectable.
  • Thick antimony alloy grids to make it suitable for long cycle life.
  • The best pick for the reserve power applications. 


  • Flooded batteries have the weakest internal construction.
  • The internal resistance statistics are slightly high.
  • Needs some regular maintenance. 

A comparison chart among sealed, GEL, and flooded batteries

A comparison chart among sealed, GEL, and flooded batteries can help you understand their dissimilarities. Here is the comparison chart to satisfy your question – “how do you tell if a battery is sealed, GEL, or flooded?”. 

Number of comparisonsSealed batteryGEL batteryFlooded battery
1A sealed battery comes with a special sealed condition which ensures the spilling of the electrolyte. A GEL battery comes with silica or sand inside of the battery. This setup helps to hold the electrolytes together. A flooded battery contains water along with 35% sulfuric acid. The movement of the electrolytes can be heard easily. 
2It’s a modified version of the flooded battery.A GEL battery is similar to the AGM battery except for its wet cell. The principle of its construction is almost the same as Daniell’s battery.
3A sealed battery is maintenance-free. The user can use it without any major care.A GEL battery is also maintenance-free as the sealed battery. A flooded battery isn’t maintenance-free. The user needs to put some water regularly inside the fixed compartment. Otherwise, the cell may get damaged by being dried over time. 
4Lasts up to 12 years. This life period depends on its usage. The user can use a GEL battery for around 10 years without complications. But, the lifespan decreases in case of heavy use. Typically, a flooded battery is less lasting than the sealed and GEL batteries. It can last from 3 to 5 years after normal use. 
5There is wide use of sealed batteries for modern automotive purposes. Highly used in medical mobility batteries and RV deep cycling batteries. This kind of battery has a special use in automotive starting. Besides, they are the best choice for deep cycling, solar use, and urgent backup.

How do you tell if a battery is sealed, GEL, or flooded?

How do you tell if a battery is sealed, GEL, or flooded

Can you determine the mentioned three types of battery easily? You can determine it with some easy tricks. 

The equation becomes super easy for a flooded battery. As we have mentioned earlier, a flooded battery is manufactured with water and sulfuric acid inside it. So, anyone can feel the presence of the liquid by shaking a flooded battery slowly. As a flooded battery isn’t heavy at all, so the user can determine it easily. But, the main problem arises with differentiating between the sealed and GEL battery. Usually, there is a label indicating that it’s a GEL battery. 

A removable cap is found at the top of a flooded battery. But, a sealed battery always comes with strict sealing. Its sealing is extremely tight as it won’t leak the electrolytes in the rough conditions limit. So, nobody can find any kind of vent, cap, or removable top case in a sealed battery. On the flip side, a flooded battery has caps for adding water. And this specification ensures a flooded battery’s identification.

Sealed vs GEL overview

Distinguishing topicSealed batteryGEL battery
Arriving conditionA sealed battery comes with a “sealed” label. But, it’s not a constant incident. There are no caps or removable top cases for a sealed battery.A GEL battery always comes with a sealing indicating its battery type. 
Period of serviceAfter regular heavy use, a sealed battery can run around 12 years. After regular and average use, a GEL battery can serve for almost 10 years.
TemperatureSealed batteries can’t run under the -30 degree celsius temperature. GEL batteries can be operated even under -60 degrees celsius temperature.
ApplicationSealed batteries are useful for modern automotive uses. From medical mobility batteries to RV deep cycles, GEL batteries are mandatory. 

1. A sealed battery comes with its “seal” tagging to warn people before using it. The GEL battery isn’t different from a sealed battery. It helps to prevent selecting the wrong battery. Besides, the sealed option ensures good protection of the user’s skin from acid accidents. 

2. Sealed batteries can perform for a long period. But, the GEL batteries perform some fewer years than a sealed battery. Perhaps, the silica or the sand in the GEL battery creates this matter. 

3. The sealed battery is okay with extremely negative temperatures. But, the GEL battery is stronger than a sealed battery in this stage. 

4. A sealed battery is suitable for operating any automotive operations in any position. On the other hand, GEL batteries have some special applications. That’s why GEL batteries are rarely familiar. 

Sealed vs flooded overview

Distinguishing topicSealed batteryFlooded battery
Arriving conditionAll the sealed batteries arrive with a specially engineered function. The function helps to prevent the electrolytes from spilling away. All the flooded batteries arrive with sufficient water and 35% sulfuric acid. It’s not sealed and the electrolytes aren’t secured like the sealed battery. 
Working principleThere is no major difference in the working principle of a sealed and flooded battery. Flooded batteries run strictly maintaining the rules of Daniel’s battery.
MaintenanceA sealed battery is maintenance-free. You don’t need to put in some water to make it usable. A flooded battery needs to put some water after a certain time. Stopping this duty can ruin the flooded battery just after a few moments. 
ApplicationThere is a large use of sealed batteries in automotive uses. The flooded batteries are helpful to start the automobiles, deep cycling, and immediate backup. 

1. Sealed battery has sealed electrolytes inside of it. It can’t be eradicated by using any caps or removable covers. But, anyone can add water, change the electrolytes of a flooded battery. 

2. A sealed battery doesn’t obey the rules of a flooded battery to the letter. But, a flooded battery is fully dependent on Daniel’s rule. 

GEL vs flooded battery overview

3. No necessity of wasting your time on adding water by maintaining a hard schedule for a sealed battery. But, a flooded battery requires this criterion.

4. The automobile industry is highly dependent on a sealed battery. On the other hand, there is a different field for a flooded battery. No battery is perfect in backup usage and deep cycling as a flooded battery. 

GEL vs flooded overview

Distinguishing topicGEL batteryFlooded battery
MaintenanceA GEL battery doesn’t need to perform extra maintenance like adding water from time to time.A flooded battery requires adding distilled water from time to time. Otherwise, the cell will die and the battery won’t perform.
Special ingredientThe presence of silica or sand makes the GEL battery special. There is no presence of silica or sand to hold the liquid inside the battery. Instead, there exists some water and sulfuric acid.
Years of serviceAll the GEL batteries are manufactured for lasting at least six years. The users can use it for 10 years without major complications. All the flooded batteries have a small life period. They can serve around three to five years. 
ApplicationThis kind of battery is widely used as a medical mobility battery. The RV deep cycle batteries and trolling motor batteries require high-performance batteries like a GEL battery. This kind of battery is a good choice for reserve power applications. In backup power, utility, telecom, and energy storage- all of there the flooded battery keeps contributing.

1. A GEL battery is maintenance-free like a sealed battery. But, there is the hassle of adding water to the flooded battery.

2. All the GEL batteries come with special construction of silica or sand. That’s designed for holding the electrolytes together. If you go for a flooded battery, it arrives with no special build. Only water and sulfuric acid exist inside. 

3. GEL batteries are long-lasting. They can serve around 6 years and some of them can last for 10 years. But, a flooded battery can’t last more than 5 years. 

4. GEL batteries are built for special uses like medical mobility. But, you can use a flooded battery for special reservation purposes. 

Which one is better?

Which one is better

It’s time for the verdict. You have a complete idea now on – “how do you tell if a battery is sealed, gel, or flooded?”. Along with this, you’ve already understood that all the batteries have their different purposes and handling methods. Despite having some similarities, there are some mentionable dissimilarities too.

A sealed battery is engineered for protecting its electrolytes. There is no chance of its extraction and hampering the human body. So, the sealed battery wins in case of safety. And if it’s about dedicated applications, the winner must be the GEL battery.

There is also a wide use of the flooded battery. Despite its maintenance inconvenience, it’s also great for some automotive and energy preservation purposes. Whatever the battery is, all of them hold some bad sides with their pros. So, pick the best battery for you according to your criteria. 

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