What is an AGM battery?
You’ve probably heard of AGM batteries and know that they stand for “adsorbed glass fiber barrier.” But what exactly does adsorbed glass fiber manifold (AGM) mean? And how does it improve battery performance over standard lead-acid batteries?
Understanding SLA Battery Construction
All sealed lead-acid (SLA) batteries consist of positive and negative plates and electrolytes arranged in “cells” inside a battery case. Some of these batteries are valve-regulated, allowing a small amount of gas produced during re-combination to be released during charging. Although gas can escape, these batteries are spill-proof (often called valve-regulated lead-acid or VRLA) and can be operated safely in almost any position (the only exception being not to use them upside down). Because they are hermetically sealed, there is no need to add electrolytes after manufacture, and any gases produced are recycled back into the battery.
AGM Battery Construction
AGM batteries retain the basic structure of a standard SLA battery, except that a fiberglass mat is added between the positive and negative plates to absorb the electrolyte. The pad functions similarly to a sponge so that the battery will not spill. The AGM design allows the electrolyte to penetrate the fiberglass pad, maximizing the plate contact area without filling the battery with excess electrolyte. The AGM battery contains only enough electrolytes to keep the pad wet, ensuring that no excess liquid will flow out of the battery in the event of damage. This design reduces the amount of electrolyte used while providing the same energy output as traditional SLA batteries.
Types of AGM Batteries
People refer to AGM batteries and associate them with deep cycle applications. However, not all AGM batteries are designed for deep cycle applications. While AGM batteries are a popular choice for deep-cycle applications – with depths of discharge (DoD) of up to 80 percent, compared to 50 percent for standard flow batteries – they are also suitable for starter applications. Their low internal resistance allows them to deliver high-current loads quickly. In addition, AGM batteries are increasingly being used as start-stop batteries in modern automobiles, as ordinary batteries often lack the durability to withstand the repeated cycling of start-stop systems, leading to premature failure.
At Techhem, we offer deep cycle AGM batteries and the preferred AGM technology in our PowerSport range. Our AGM products include the Super Sport, Ultra Sport AGM and Stop-Start AGM series. In addition, AGM technology is used in our General Purpose and Long Life product lines because the fiberglass spacer optimizes the electrolyte surface area to improve battery performance.
Each cell in an AGM battery produces 2 volts, and these batteries are available in a variety of voltages, including the popular 6-volt and 12-volt models.
Charging AGM Batteries
One of the major advantages of AGM batteries is that they charge up to 5 times faster than standard lead acid batteries. However, AGM batteries are very sensitive to overcharging like all sealed lead acid batteries. We recommend that you follow the charging guidelines for sealed lead acid batteries to maximize the life and performance of your AGM batteries.
Can AGM batteries be recycled?
Yes, AGM batteries can be recycled. the recycling rate for AGM batteries is over 98%. The battery industry prides itself on the fact that lead-acid batteries have one of the highest recycling rates in the world.AGM batteries are environmentally friendly and easy to recycle, and recycling is available at most centers, auto dealerships, and many other locations.
AGM Batteries vs Liquid Rich Batteries
Advantages of AGM Batteries
AGM (Absorbed Glass Fiber Mesa) technology offers a number of advantages over traditional flooded battery designs. One of the major advantages is the ability of the glass fiber spacer to retain acid, thus reducing the potential for sulfation. AGM batteries have a deeper depth of discharge (DoD) than flooded batteries.
In addition, AGM batteries have lower internal resistance and, therefore, lower self-discharge rates. As a result, they do not require frequent charging during long-term storage. It should be noted that AGM batteries still need to be charged before storage and require maintenance charging when not in use for extended periods of time, but they charge faster than regular batteries.
AGM batteries have the advantages of faster charging, longer cycle life, and greater vibration resistance than regular batteries.AGM batteries are ideal for power sports applications because of their close-packed design and internal cushioning for vibration damping. In addition, AGM batteries use less electrolytes than regular batteries, resulting in a lighter overall weight.
However, one of the drawbacks of AGM batteries is that they cost more than regular batteries. Due to this price difference, regular batteries still dominate the market, especially in motorsports.
AGM Batteries vs. Gel Batteries
In addition to liquid and AGM batteries, gel batteries are another popular alternative. Gel batteries also require no maintenance, feature sealed cells, and utilize a reconstitution process to prevent gases from escaping. The main difference between gel batteries is that their electrolyte is a thixotropic gel-like sulfuric acid.
Comparing gel batteries to AGM batteries, it can be seen that the rated capacity of gel batteries decreases rapidly with decreasing ambient temperature (below 32 degrees Fahrenheit). Also, gel batteries perform poorly in high current or starter applications, making them less common in power sports scenarios. Conversely, gel batteries are much less acidic and may have a longer lifespan in some applications. Cohen offers DCG (Deep Cycle Gel) and 2-volt OPzV tubular gel series gel batteries.
AGM and Lithium Batteries
There are some differences between AGM batteries and lithium batteries. Understanding your specific requirements is critical when choosing the right battery. Are you looking for a deep cycle application, a high rate discharge application, or a float standby application? Does your application already have a built-in charger designed for your specific battery chemistry? What is your budget?
Cohan has compiled a comprehensive guide detailing the differences between sealed lead-acid and lithium-iron phosphate batteries that can help you determine if AGM batteries are the best choice for your application.
In summary, depending on your application and budget, you will find that AGM batteries are superior to regular batteries because they are lighter in weight, require less maintenance, and offer more all-around performance. AGM batteries are often preferred over gel batteries because they are more readily available and often less expensive. Ultimately, depending on your specific application and desired results, you’ll need to choose between AGM batteries and lithium batteries.