How do I know if my battery is AGM?

I hope you agree with me when I say:

 The answer to the question of how do I know if my battery is AGM might be simple than you think, as long as you follow the right direction 

Batteries are exceptionally crucial in empowering our day-to-day life. We come in contact with them whether in the form of mobile accessories or in transport vehicles like RVs. As the technology behind them has progressed, they have improvised us into the modern-day tech revolution. One such battery type that you have seen or probably heard about is the Absorbent Glass Mat or AGM. The main difference between AGM and the standard battery is the charge predictably.

Generally speaking, AGM batteries consist of a thin ultra-fine fiberglass mat between the inner plates, which prevents them from suffocation and enhances their longevity. This way, they are precisely engineered to tackle modern-day power demands. Conversely, have you ever wondered what does AGM on a battery means?

As you might know, at first glance, an interstate glass mat battery might be similar to its traditional counterpart based on construction, but internally, they are a lot different. That’s why it’s difficult to tell if the battery is AGM, which is why today we will discuss how to tell if the battery is AGM. So, let’s get into it!

Everything to know About AGM Battery

For average do-yourself homeowners, the whole AGM concept might be new; thus, they often get confused when answering questions like what does AGM means on a battery charger? How to determine the type of battery? & why buy an AGM battery? Following are some answers to these kinds of queries;

AGM battery definition / what is an AGM battery type?

Now, what is an AGM battery type? An AGM or Absorbent Glass Matt is a type of battery that incorporates glass matt construction to absorb the battery’s acid. This way, the conductive electrolyte solution will be held tight against the walls of the container or plates, leading to greater efficiency.

For those who are wondering, what does an AGM battery look like? There is ergonomically stable 99.9% lead platting inside them, which is tightly wounded and compressed to oppose several drawbacks from their conventional counterparts. AGM Batteries share twice the capacity of standard models, and they are meant for cars with higher power requirements. We hope this clears the AGM battery definition or what AGM stands for on a battery charger!

AGM vs. Standard Battery – Difference between AGM and Standard Battery

Batteries have dramatically evolved over the years from the traditional models where you were required to take off the caps and add water over a month, to the maintenance-free conventional batteries, to capacitor-type systems and now newer AGMs. When we talk about AGM vs. Standard Battery, the number one thing that differentiates them from each other is that standard models are concerned with venting and the battery’s position.

So, if you tilt them aside, there is a high chance that the electrolyte solution might spill out. However, that’s not the case with AGM, as there is a special type of material within the plates that absorb that electrolyte and prevent it from spillage. The other difference between AGM and the standard battery is that the absorbent matt variants have so-called recombinant vents that keep the vapors within the battery and thus make AGM car batteries worth the money.

Looking for standard batteries? Check out our related article on 9 Best 24F Batteries to Buy in 2021【Reviewed】

Benefits of an AGM Battery – Why Buy an AGM battery?

Lead-acid batteries have been mainstreamed in automobiles and other accessories, but with the rise of power demands, most average consumers are switching to AGM designs. They might be a bit costly than standard models, but they offer many advantages that cannot be easily compensated. Some of their features include alternate decoupling, regenerative braking, and stop-start, while others are summarized as;

Advantages of AGM

1)   Spill-proof construction

AGM batteries feature glass-matt construction, which holds the electrolyte solution, tight inside the container, thus greatly minimizes leakage. This is an optimal way to tell if you have an AGM battery.

2)   Vibration-resistant performance

Due to their advanced design, AGM batteries not only enhance the cold cranking power but also protect themselves from subtle vibration during high load.

3)   Higher charge & discharge rate

When it comes to maintaining integrity (charge & dis-charge cycles), AGMs have an advantage. Throughout the start and stop cycles of an auto-mobile, AGM batteries operate on their own and supply power to various components without disrupting overall efficiency. So, if you’re wondering, how do I know if my battery is AGM? it would help if you simply analyzed the power draw.

4)   Lack of rapid overheating

If your RV has a generative setup, then getting an AGM is a must. Due to greater capacity, they will recycle the excess energy dissipation rapidly and show no signs of overheating and even overcharging. This is the reason they are often preferred in various dry cell car battery reviews.

Looking for RV acessories? then make sure to check out 6 Best RV Holding Tank Treatment In 2021【Quick Action】

5)   Lower maintenance & drainage

For those who are wondering, what does AGM stand for on a battery charger? They simply need to observe their vehicle system. If your car or RV has a large number of accessories or appliances such as electric doors, automated-GPS system, deck ports, and infotainment setup, then you defiantly want to invest in an AGM as they drain quite inferior throughout the course. This feature truly makes AGM car batteries worth the money.

Hopefully, this might clear confusion about what is an AGM battery type? Or what does an AGM battery look like? AGM vs. standard battery, and Do I need an AGM battery?

Best Approaches on how do I know if my battery is AGM?

After going through basic AGM battery definition and covering other aspects, why buy an AGM battery, or do I need an AGM battery? It’s time to explain how to tell if you have an AGM battery. It’s worth noting that batteries appear in a variety of designs, each tailored to a specific application and price point. So, it’s better to consult their category so you can handle them according to their requirements. Following are some of the common ways to tell if the battery is AGM;

a)   Reading the labels

One of the easiest and most effective ways to tell if you have an AGM battery or to determine the type of battery is simply by observing the battery labels over your model. Typically, AGM batteries come in solid construction and are labeled with words like “Absorbed Glass Mat” or “dry cell.” While others tend to reside with “valve regulated” or “sealed regulated valve.” If you still can’t find the labels you’re looking for, search for stamp catalogs with “non-spill” text on the side walls.

In contrast, for those with liquid batteries or flooded-lead-acid batteries, finding texts like “wet cell” or “liquid lead acid” is common. Also, lead-acid batteries are available in semi-liquid configuration, so don’t get confused if you find wordings like “Gel-Filled” over the labels.

b)   Searching for online details

If observing labeling tags is a bit hard for you or isn’t located on your battery, then the best practice is to look for online resources. Depending on your manufacturer, information like model number and batch details can easily be found over the internet. Additionally, with a bit of research, you can also contact a company representative and can quickly tell if the battery is AGM or not. Trust us, you won’t have to search “how do I know if my battery is AGM” and even “what is an AGM battery type” again!

c)   Finding the AGM caps

Sometimes information on how to tell if the battery is AGM is not that straightforward, so you need to look out for things like cap configuration. The majority of modern batteries incorporate caps or removable ends at the top surface. If your battery is designated with flat tops and contains positive and negative endpoints, it is likely AGM-based. However, that’s not the case with any liquid lead-acid type battery as their top is “sealed” or enclosed. So, to tell if you have an AGM battery, make sure to give the end-caps a short look.

d)   Checking the fluidity

Still can’t tell if the battery is AGM or not? Well, why not check the fluidity of the given electrolyte. This can be done by gently shaking the battery. So, if you boast a lead-acid battery, you will feel a bit of wiggle as the container is shaken. Due to greater fluidity, this self-centered motion can even be observed even if the battery is covered. However, for AGM models, this wiggle is not present due to tight internal glass-matt packaging. The same could be said for any gel car battery. Anyhow, before you perform this activity, make sure to equip protection Googles and rubber gloves for safety protocols.

Top 5 AGM Batteries to Buy In 2021

Now that you can tell if the battery is AGM or what kind of car battery you have, it’s time to look into some of the additional premium AGM batteries for the money in 2021. Each of them is known for its features and price-point, so you might be able to choose a model specific to your needs. Other than that, each of these AGM car batteries is worth the money, as suggested by various dry cell car battery reviews.

Overall Best

Best budget




Product Name ODYSSEY 31-PC2150S Optima Batteries 8006-006 Vmaxtanks VMAXSLR125 Universal Power Group VMAX MR127
Key Features ·        Highly durable construction

·        70 percentage longer cycle

·        -40 to 45-degree Celsius operation

·        Ergonomic design

·        100 minutes of reserve capacity

·        15X Vibration resistant

·        Best deep cycle battery

·        8 to 10 years of lifespan

·        Solar power charger

·        Light weight construction

·        Ideal power consumption

·        Beneficial for minimal usage

·        Maintenance-free design

·        Equipped with Electrolyte Suspension system

·        Heavy Duty Alloy Grids

Volts 12V 12 V 12V 12V 12V
Amp/Hour 18 20 34 to 40 10 100
Overall weight 77.8 Pounds 38.4 Pounds 75 Pounds 8 pounds 65 pounds
Price $402.99 $269.99 $289.99 $28.19 $274.99
Warranty 3-4 years 36 months 1 year 1 year 1 year

A helpful tip in determining the type of battery is by first asking yourself what type of battery do I have and then making adjustments according to those power regulations. Furthermore, if you do need an AGM battery, then make sure to choose the model with added warranty, as it does take a bit of time to determine what does AGM on a battery means.


In conclusion, this was an essential guide to detecting what kind of car battery you have and what does AGM means on a battery charger. Now, if the question of what type of battery do I have correlates with AGM, then it’s no doubt a great thing, but you will require to take special care of it in the long run. You might not know, but AGM batteries can be easily damaged with excessive charging voltage.

As the battery pressure rises above a certain specification due to excessive charging, the recombinant vent opens up, and that’s when you will notice quick degradation in their health. The same principle can be applied no matter what kind of car battery you have, so try to take extra care.

FAQs - Related Questions

Q1, How do AGM batteries work?

AGM batteries operate through absorbent glass mat construction within the container that tightly held the electrolyte solution. Under high pressure, it results in a charge that is quite stable.

Q2, How long does an AGM battery last?

Well, it majorly depends on what type of battery is in your car. Most types of 12v batteries in AGM configuration like interstate srm-29 on amazon last 5-6 years under ambient room temperature.

Q3, Why is AGM battery better than traditional models?

When we talk about sealed lead acid batteries vs. AGM, the absorbed glass mat motorcycle batteries are generally better since they are resistant to spillage and vibration and hold several other prime features.

Q4, How do I know if my battery is AGM or standard?

AGM batteries are available in a non-liquid format so shaking the battery itself is an easy yet efficient way to know its existence.

Q5, Are all AGM batteries deep cycle?

It is a common misconception, but not all AGM batteries come in the deep channel configuration. However, for those of you who are asking if AGM batteries lead acid, then yes, it might be true to an extent.


Hey! I’m Mark Polk, an author, camper & public speaker on anything & everything RV related. I have educated millions of RV consumers on safely and properly usage through my movies (i.e. TRV Education 101: RV Care and Maintenance 2009) Writing about this industry is a huge passion of mine, so here’s a little piece of my mind.