AGM vs. Lithium: 6 Differences to Consider

In order to fully utilize and store power from renewable sources, a reliable battery storage system is required. Nowadays, the use of renewable energies (Solar, wind and, hydro technology) is not only restricted to private use alone. It has made its way into mainstream development.

With this development, most people now have to make decisions on choosing the most suitable battery to store energy. There are several types of batteries but AGM (Absorbed Glass Mat) and Lithium-ion batteries are the most talked about. So in this article, we will share with you some of their properties of AGM vs lithium for you to decide which is best for you.

The Basic Intro to Lithium vs AGM

A lot of people may find it hard to choose when it comes to agm versus Lithium batteries because they both have certain advantages that scale them above each other, but nevertheless, we still need to make that tough decision.

Lithium Battery 

Just like all batteries, lithium allows the flow of electrons between its two electrical terminals. It is rated as one of the best batteries due to its recharging feature, coupled with great storage capability and high energy density.

Lithium Energy Storage Battery
Source: LiFePO4 Battery for Home Solar System

This battery is made up of three major components known as; Electrolyte, Anode, and Cathode. Lithium batteries begin to charge when electrons move from the Cathode to the Anode and discharge when electrons move from the Anode to the Cathode(Learn: A Comprehensive Guide for Anode and Cathode of Diode).

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Lithium batteries can be found in most phones, laptops, and recently, it has been integrated with some everyday items like wheelchairs, hearing aids, pacemakers, etc.

AGM Battery

The AGM battery remains a great competition as it is designed to be totally leak-free. It is also referred to as Gel battery because it is powered by agar gel electrolyte and not the standard liquid electrolyte. Unlike other batteries whose electrolyte liquid floats around, The AGM battery’s electrolyte liquid (battery acid) is fully absorbed by a woven fiberglass mat.

Out of the three types of Lead-acid batteries there is, AGM is the latest and most efficient edition. Due to zero to no maintenance during use, it is often integrated with renewable energy supplies for automobile, residential, and other appliances. AGM batteries are light, less expensive, and just like lithium-ion batteries – they are rechargeable. 

6 Differences Between Lithium and AGM Batteries 

Before deciding to go for either of these battery-types, it is of great significance to note the properties that make them different from each other. Discussed below is the difference between agm and Lithium battery for you to make an informed decision. 

Different Lithium Batteries
Different Lithium Batteries

1. Different Depth of Discharge

The Depth of Discharge also known as DoD refers to the percentage extent to which a battery can be discharged without being damaged. It can be calculated by estimating the capacity that has been discharged from a fully charged battery, divided by the batteries nominal capacity. This is often expressed in percentage. So whenever a battery gets discharged beyond required limits, it begins to suffer damages.

Lithium batteries allow for full exploration of its capacity as its depth of discharge ranges from about 95%-98%. This simply means almost all the initial charge can be discharged without causing any damage to the battery life.

A new AGM battery may have a DoD of 80% at first, but with time, the capacity reduces to the extent that it would no longer serve its purpose. So in terms of DoD, Lithium batteries are more reliable as they possess higher capacity for discharge and are less prone to damages.

2. Differences on Battery’s Lifespan 

The two major factors that influence battery lifespan are the maximum depth of discharge and the number of charging cycles. When these factors are being exceeded, the battery electrolyte begins to wear out thereby reducing the performance and lifespan.

When the required DoD specifications are followed strictly, lithium battery capacity may only reduce by 1% yearly, and its charge cycle can range between 500 to 4000 times. Unlike the AGM battery whose charge cycle stays below 800 times. For the perfect brand selection, the Polinovel power wall LiFePO4 lithium battery life only reduces by 1% every year and has up to 5000 charging cycles. 

Once again, lithium batteries stand ahead in terms of battery life. Its charge cycle and DoD can make it span from 10 to 15 years, unlike the AGM battery that only lasts between 2 to 3 years.

3. AGM vs Lithium Batteries: Different Size and Weight 

With the incessant development of battery technology, size and weight does not always determine the battery’s capacity anymore. Some batteries tend to be smaller in size but contain much more capacity than bigger ones. Size and weight are mostly considered when there is limited space.

Lithium battery typically holds a lesser size and weight because its electrodes are made of lightweight lithium and carbon. Meanwhile, AGM weighs higher as a result of absorbed liquid acid. Due to this, a 120Ah lithium battery weighs 16kg, while a 120Ah AGM battery weighs 32kg approximately.

Also in this case of lithium battery vs agm, the former is the best as it weighs less, occupies less space, and is more efficient. 

4. Differences on Energy Density

The energy density of a battery refers to the amount of energy a battery can contain with respect to its weight and size. Energy density can be calculated by dividing battery Watt-hour (Wh) by its kilogram or volume.

Lithium batteries have the highest amount of energy density because they are capable of storing more energy per mass and require less space when compared to AGM batteries. They have a density of 100-265 Wh/kg and 260-270 Wh/L. 

Battery energy density is considered when producing a device that requires high energy output but not enough battery space. This is why lithium batteries are present in mobile phones, digital cameras, and other handheld devices.

5. Different Charging Time

Another disparity of AGM vs lithium battery is charging time. This is the amount of time it takes a battery to complete a full charge. Fast charging is one of the key features of lithium batteries and this is as a result of lesser electrical losses. In terms of comparison, lithium batteries are capable of charging faster than AGM batteries with the same Wh.

Averagely, AGM full charge may take up to 8 hours, while lithium battery full charge may be as low as 2 hours. The presence of low resistance in lithium battery cells allows it to accept full output from its charger, hence an early charging time when compared to AGM.

6. Different Initial Cost of AGM Battery vs Lithium 

Cost is one factor to consider when choosing battery type. A few people tend to go for AGM batteries because it is quite cheaper, but when you consider its short lifespan, you might end up spending more than you would have spent on a lithium battery in the long run.

Lithium battery is a reliable product that holds high value. Therefore, the amount and quality used in production will always drive the consumer price up. So the only reason to place AGM batteries ahead of lithium is cost. 

Reliable Lithium Batteries Manufacturer in China: Polinovel

There are a whole lot of lithium battery manufacturers out there, but if all you want is a product that stands out in terms of innovation and quality, Polinovel is where you should be. As a leading lithium batteries manufacturer, Polinovel specialize in the manufacturing and bulk distribution of outstanding lithium batteries for Solar System, RV Trailers, Golf Carts and Marine applications.

LiFePO4 Bluetooth Battery
LiFePO4 Bluetooth Battery

We have been in the business for over 15 years and have amassed more than enough experience, research, and qualification to cater to all your requirements. At Polinovel, customer satisfaction is our core priority because we believe a happy customer will always find their way back through frequent referrals and recommendations.

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We offer several options that are suitable for various applications, such as the Polinovel Light EV Battery. It is a moderate price battery designed to easily kick start large engines. It can be applied in Cars, Motorcycle ATV’s, Marine boats, and other fields that need a whole lot of cranking discharge characteristics. We also provide top notch customer service to know the most suitable battery that will serve you best.


Ever since the rise in demand for renewable energy, discussions about batteries have been all over the internet. And for now, AGM vs lithium batteries have found their way to the top of the discussion.

When you try to compare agm or lithium battery, lithium battery is far ahead of AGM’s. Although the initial cost of acquiring an AGM battery is cheaper, its short lifespan would result in spending more in the long run. Morevore, choosing a reliable lithium batteries manufacturer can make your product stand out!

FAQ About AGM Versus Lithium Batteries

Frequently, lots of people find the need to ask questions about lithium vs AGM batteries. The main purpose is to know which is best before making a purchase. Below are some of these questions and relative answers to hasten your lithium vs AGM battery research/purchase.

Are AGM Batteries Better Than Lithium Batteries 

No, lithium batteries are better because they are lighter and are capable of storing more energy for the same amount of space. They are also better in terms of charging time, energy density and battery lifespan. Finally, unlike AGM batteries, lithium batteries can discharge about 95%-98% of their initial charge without causing any damage to their battery life.

Can AGM and Lithium Batteries be Used Together

Yes, they can, but doing this may drastically affect both battery lifespan. If the resting voltage of the AGM battery is lower than that of the lithium battery, the lithium battery will always drain into the AMG and later on, it will drain back to the lithium. However, they can be paired if a battery isolator is used.

Can You Replace an AGM Battery With Lithium Battery

Yes, it is possible to replace an AGM battery with a lithium battery, because lithium batteries have higher power than AGM batteries. Even if it is replaced with a lower capacity, it is still capable of offering twice as much power than an AGM battery.

Although when it comes to some automobiles, the answer might be no. This is because some lithium batteries rely on BMS (battery monitoring system) to regulate charge and prevent it from deep discharge. If the BMS is not installed alongside the battery, there might be complications. For more information and guidance to make an informed decision, contact us for full support.

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