Difference of Li-Ion and AGM Battery

Did you ever wonder about the difference between AGM and Lithium-ion batteries?        

Now a days energy storage is one of the main components in almost every aspect of life. Efficient energy storage is needed for the smooth operations of various industries. Batteries have become the staple for energy storage. There are many batteries available in the market for storage purposes such as Lithium-ion, AGM etc. In this article we will discuss the difference between these storage devices. ?

Absorbent Glass Mat (AGM) Battery:

An Absorbent Glass Mat (AGM) battery has two plates: a positive and a negative plate. These plates are made of a glass mat that absorbs acid. Unlike traditional lead-acid batteries, AGM batteries don't contain free-flowing acid making it maintenance free.

Lithium Ion Battery:

A Lithium-ion battery utilizes Lithium as electrodes. During charging, Lithium ions move from the positive to the negative electrodes via an electrolyte. When the battery is charged and the charger is disconnected, the ions return from the negative electrode to the positive electrode, generating current.

Comparison between Li-ion and AGM batteries:

1) Depth of Discharge

Battery suffers when you discharge a battery beyond specific limit. DoD measure the percentage of the initial charge that can safely be discharged without causing harm.

Li-Ion Batteries: Modern Li-ion batteries have a depth of discharge (DoD) of over 80%, allowing for almost the entire charge to be used without damaging the battery.

AGM Batteries: These batteries have a lower DoD compared to Li-ion batteries. Discharging them beyond their recommended limit can result in damage to the battery.

2) Lifespan

Regardless of type, batteries experience a gradual decrease in performance over time, eventually reaching a point where they become unusable.

Lithium Batteries: Li-ion technology is renowned for its superior durability, typically degrading by less than 1% per year and offering approximately over 7000 charge cycles.

AGM Batteries: These degrade more quickly, with a useful lifespan of around 1000 charge/discharge cycles.

3) Size and Weight

Size is a crucial consideration if you have limited space.

Lithium Batteries: Lithium-ion batteries are lighter in weight due to the absence of liquid acid. Moreover, their higher depth of discharge allows a smaller lithium-ion battery to deliver the same power as a larger AGM battery.

AGM Batteries: AGM batteries contain absorbed liquid acid, adding weight. Additionally, their low depth of discharge necessitates a higher-capacity (larger) battery for a given application.

4) Charge Time and Efficiency

Charge time and efficiency refer to the duration it takes to charge a battery and how effectively it converts energy during that process.

Lithium-Ion Batteries: Smaller in size li-ion batteries, with their higher efficiency, can accomplish tasks equivalent to larger AGM batteries while charging more rapidly

AGM Batteries: While AGM batteries charge considerably faster than wet lead-acid batteries, they still charge much slower when compared to lithium-ion batteries.

5) Initial Cost

Cost is a crucial factor when choosing between battery types, with two main considerations: the initial cost and the cost per kWh. Lithium-ion batteries entail a higher upfront cost. Despite outperforming AGM batteries across various parameters, their initial cost is significantly higher.