AGM vs. GEL battery & AGM vs. lead acid (What you need to know)

AGM batteries are frequently mistaken for gel cell batteries. Both AGM and GEL batteries may be mounted in any position, have low self-discharge, are safe to use in regions with limited airflow, and can be transported via air or ground safely and without special treatment. These are just a few of the similarities between the two types of batteries. It’s hardly news that AGM batteries provide more benefits than gel batteries. AGM batteries outsell gel batteries by a ratio of roughly 100 to 1.

AGM vs. GEL battery

The cost difference is the primary cause of this. AGM batteries cost less than gel batteries. Furthermore, AGM batteries are the best option because they also have several beneficial features. High-quality AGM batteries perform well across a wide range of temperatures. They are excellent for all high amp applications and have a very slow self-discharge rate, thus leaving one plugged in will not result in significant energy loss.

Well, in this article, we’ll be looking at AGM vs. GEL battery. We’ll also be looking at AGM vs. lead acid. Nevertheless, we’ll get to discuss the answers to the following questions:

  • What are AGM and GEL batteries?
  • What are the differences between AGM and GEL batteries?
  • Which is better, AGM or GEL battery?

Read more: Lists of best car battery

Alright then, let’s get to it.


What are AGM and GEL batteries?

AGM battery

AGM (absorbed glass mat) uses a special type of glass mat that is intended to wick the battery electrolyte between the battery plates. The liquid in AGM batteries is only enough to keep the mat moist with electrolytes, and if the battery breaks, no free liquid can escape. This advanced lead-acid battery known as AGM, or absorbent glass mat, offers superior power to satisfy the greater electrical demands of contemporary automobiles and start-stop applications. AGM batteries are completely sealed, spill-proof, and vibration-resistant in addition to being maintenance-free. When compared to traditional lead-acid batteries, AGM delivers superior cycling performance, less gassing, and less acid leakage. Superior life performance is the result of all the attributes of AGM technology.

GEL battery

A gel battery is a valve-regulated, maintenance-free lead acid battery. Gel batteries are incredibly durable and adaptable. These batteries can be utilized in locations with limited ventilation because they emit fewer emissions. A gel battery is a valve-regulated, lead-acid battery that combines silica fumes with an electrolyte in a predetermined amount of sulfuric acid. The immobile, gel-like mass produced by this chemical reaction is what gives these batteries their name. The battery electrolyte is suspended in a silica-type gel that is found in gel cell batteries; this thick paste-like substance allows electrons to move between plates but won’t leak from the battery if the case is cracked.

Read more: Battery light on in car: meaning, causes, & what to do when the light appears on the dashboard

What are the differences between AGM and GEL batteries?

AGM vs. GEL battery

The main difference between GEL and AGM batteries is how they are made; GEL deep cycle batteries use a gel paste in which the electrolyte is suspended inside the battery case. AGM batteries have the significant safety advantage of having the electrolyte whipped up into a glass matt interior, where it can never leak.

Here are some other major differences between AGM and GEL batteries:

AGM battery GEL battery
AGM stands for Absorbed Glass Mat GEL stands for Gel electrolyte
Faster charging rate Slower charging rate
Widely used in automotive and marine industries Widely used in backup power and renewable energy systems
The acid electrolyte is absorbed by a fiberglass mat The electrolyte is mixed with silica to form a gel-like substance
Slightly less expensive Slightly more expensive than AGM
Longer lifespan in warmer temperatures Longer lifespan in cooler temperatures
Can handle higher discharge rates Lower discharge rates than AGM

It’s important to keep in mind that depending on the brand and model, certain features of AGM and GEL batteries may vary.

Read more: Lists of best car battery charger

Which is better, AGM or GEL battery?

The selection of an AGM or GEL battery relies on the particular application and needs, hence there is no universally applicable response to this query. There are benefits and drawbacks to both battery types. AGM batteries are appropriate for applications like the automotive and marine industries since they are often more cheap and capable of handling higher discharge rates. In addition, they may be charged more quickly in warmer climates and have a longer lifespan.

The deep discharge tolerance of GEL batteries, on the other hand, makes them appropriate for backup power and renewable energy systems. Moreover, they are more suitable for low discharge rates and have a longer lifespan in lower temperatures. The particular application and needs will ultimately determine whether AGM or GEL batteries are best. To choose the finest battery for your requirements, it is best to speak with a professional.

Read more: Lists of best battery maintainers

AGM vs. lead acid

AGM vs. lead acid

Technically speaking, the base chemistry of an AGM battery and a regular lead-acid battery is identical. Both of them use lead plates and a sulfuric acid and water electrolyte, which causes a chemical reaction that results in the production of hydrogen and oxygen as a by-product. Lead plates are submerged in liquid electrolytes in flooded lead acid batteries (FLA batteries).

Water is lost as a result of the gases released into the atmosphere as a result of the chemical reaction. The electrolyte levels, therefore, require regular replenishing. Fiberglass mats are positioned between lead plates in the AGM battery. It’s where the battery gets its name, Absorbent Glass Mat (AGM). The electrolyte solution isn’t free-flowing because the glass mat wicks it, keeping it suspended. Because the AGM battery is sealed, off-gassing is minimal to non-existent.

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The electrolyte and gases created by the chemical process recombined. Moreover, a vent lets out extra gas if necessary to maintain internal pressure (for instance, when the battery is overcharged). The AGM battery requires minimal maintenance and can be installed in more restricted spaces because there is no off-gassing other than brief venting. It is best used in vehicles with batteries in the trunk and behind the seats, as well as in places where maintenance may be challenging. The flooded battery, on the other hand, needs frequent electrolyte maintenance and must be placed in a well-ventilated area because it emits fumes and steam.

Read more: How to properly recycle or dispose a battery

AGM vs. lead acid: 10 key differences

Here are ten major differences between AGM and lead acid batteries:

Durability, Vibration and Shock Resistance

AGM batteries tend to be more durable than flooded lead acid batteries because they were initially designed for use in aircraft and the military. The glass mat and battery plates of the AGM battery are sandwiched, which results in parts that don’t disintegrate readily. This design produces a battery that is resistant to shock and vibration, making them popular in race vehicles and motorbikes. Flooded battery plates can be harmed by jarring motions and strong vibrations, thus it’s important to mount them safely.

Mounting Flexibility and Spillage

The AGM battery is position-insensitive and spill-proof thanks to its glass mat technology. It can be positioned in a variety of ways, but never upside down. Yet, the flooded cell battery must always remain upright because it contains a liquid electrolyte. If spilled electrolyte is not cleaned up, corrosion may result.

Internal Resistance and Power Output

Of the numerous lead acid batteries, the AGM battery has one of the lowest internal resistances. A new AGM battery can have an internal resistance of around 2%, compared to the 10-15% of a new flooded lead acid battery. Battery voltage output is boosted by low internal resistance. Moreover, it means that less heat will be lost when the system’s electricity flows. In comparison to gel or flooded lead acid batteries, AGM batteries react to loading better. These are the preferred lead acid variant for start-stop vehicles due to their ability to manage high power demands.

Charging Time

Faster charging periods are another benefit of the AGM battery’s low internal resistance. When using the same power source, the speed of a flooded lead acid battery can be up to 5 times faster than that of a lithium battery.

Depth of Discharge

The depth of discharge (DoD) of AGM batteries is 80%, which is higher than the 50% DoD of flooded cell batteries. The AGM battery is therefore a good choice for deep-cycle applications. Yet unlike the lithium battery, which can be fully discharged, neither battery type should be depleted below 50% of its capacity. Note: The Depth of Discharge shows the maximum amount of battery capacity that can be discharged without damaging the battery.

Temperature Tolerance

In general, the AGM battery performs better across the board and has a propensity for good Cold Cranking Amp (CCA) ratings. When frozen, the electrolyte contained in the glass mat does not expand like a liquid. AGM batteries are hence resistant to harm from cold temperatures. Hence, even though the battery is unlikely to function in a cold environment, it won’t break. On the other hand, flooded lead acid batteries will freeze in the cold. The enclosures can expand and leak, and the battery plates can break. The flooded lead acid battery will evaporate more electrolytes in high temperatures, putting the battery plates at risk of exposure to the atmosphere (the lead plates need to stay submerged).

Sensitivity to Overcharging

AGM batteries are substantially less tolerant of overcharging than flooded lead acid batteries. AGM batteries are more vulnerable to thermal runaway because of their sealed design, which can be brought on by overcharging. Even if thermal runaway is ignored, overcharging will reduce the lifespan of an AGM battery more quickly. Hence, to regulate the voltage and current entering an AGM battery during charging, utilize a regulated battery charger. You should note that thermal runaway occurs when a battery produces more heat than it can efficiently expel. In severe circumstances, the battery may melt, dry out, leak hazardous chemicals, spark fires, or explode. Batteries nearby will be impacted, which might cause a domino effect.

Lifespan and Self-Discharge

AGM batteries often have a longer lifespan than conventional lead-acid batteries. The AGM batteries last longer than flooded lead acid batteries while not in use because of their low self-discharge rates. AGM batteries can last up to 7 years with proper maintenance, but flooded batteries normally last 3-5 years. If your automobile struggles to start, your battery may need repair.

Corrosion and Sulfation

Since it can vent acidic steam and is more likely to spill and leak electrolyte liquids than an AGM battery, flooded batteries are more susceptible to corrosion than AGM batteries. However, if both batteries are kept discharged for too long, Sulfation will occur. AGM batteries, however, are slightly more resilient, in part as a result of their slower self-discharge rate. It’s probably time to get in touch with your mechanic for a replacement battery if you see significant corrosion on your battery terminals.


As a starter battery for regular autos, the flooded battery is affordable and dependable. AGM batteries can cost up to two to three times as much as regular batteries.

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Frequently asked questions about (AGM vs. GEL battery and AGM vs. lead acid)

Is the AGM battery the same as the gel?

There is a common misconception that AGM and gel batteries are interchangeable. This is so because they share a basic set of qualities. Both cannot spill. They are both flexible, provide deep cycles, and can be installed anywhere.

What is the main disadvantage of an AGM battery?

When compared to a conventional flooded lead-acid battery, an AGM battery’s primary drawback is its higher upfront cost.

What are the disadvantages of a gel battery?

Disadvantages of Gel batteries include:

  • high upfront costs.
  • Water cannot be filled up again after an overcharge.
  • There is a need for unique chargers and regulators.
  • Acid can negatively affect hot temperatures by hardening the gel and causing it to pull away from plates.

Is a gel battery better?

Moreover, research has shown that in extremely cold temperatures, 12V gel batteries outlast lead-acid batteries. Between an amazing -40 degrees Fahrenheit and 140 degrees Fahrenheit, these kinds of batteries can function properly.

How many years will a gel battery last?

Since they have a very low drain rate and have been utilized in the industry for almost 40 years, gel batteries are great choices for all emergency applications. For instance, due to their lifespan of 10 to 20 years, you can find them in hospital generators.

Read more: Understanding battery used in automobiles

Which type of battery is best?

With the highest energy density of any battery cell, lithium batteries are made of this incredibly light metal. As a result, they have a higher energy capacity than alkaline batteries or any other single-use battery of a similar size. Also, they work admirably in both hot and cold environments.

Is AGM better than lead acid?

AGM batteries offer superior cycling and faster charging performance than traditional lead-acid batteries. AGM batteries exhibit low acid leakage and gassing, endure longer, and are not susceptible to freezing.

What is the main disadvantage of an AGM battery?

Comparing an AGM battery to a conventional flooded lead-acid battery, the upfront expense is its main disadvantage.

Can I use an AGM battery instead of lead acid?

AGM batteries, also known as absorbed glass mat batteries, gained popularity in the 1980s. Today, you may find them in regular automobiles and trucks. Formerly, they were only found in motorcycles, military vehicles, aircraft, and submarines. Traditional flooded lead-acid batteries can be replaced with maintenance-free AGM batteries.

Do AGM batteries last longer than lead-acid?

AGM batteries often have a longer lifespan than conventional lead-acid batteries.  AGM batteries have a lower self-discharge rate than their flooded counterparts, which extends their usable life. Additionally, AGM batteries can last up to 7 years with proper maintenance, but flooded batteries normally last 3-5 years.

What causes AGM batteries to fail?

The battery may have been harmed by sulfation, overcharging, or undercharging if the charge level of a fully charged AGM battery is less than 20% of a fully charged voltage level. A desulfation device or even changing the battery can make it better.

Can AGM battery be fully discharged?

Lead acid batteries can be discharged to 80%, whereas deep cycle A.G.M. batteries can only be discharged to 50%. The lead acid battery may now operate appliances for a longer period after just one charge.

That is all for this article, where we looked at AGM vs. GEL battery. We also took look at AGM vs. lead acid. Furthermore, we get to discuss the answers to the following questions:

  • What are AGM and GEL batteries?
  • What are the differences between AGM and GEL batteries?
  • Which is better, AGM or GEL battery?

I hope you learn a lot from the reading. If you do, kindly share it with others. Thanks for reading; see you around!