AGM or gel battery? Comparison of AGM and gel batteries

Batteries are used in most industrial applications. In most cases, they rely on solutions with high performance, reliability and ability to work in harsh conditions. Of the many types of batteries on the market, the most common are maintenance free AGM and gel batteries.

AGM or gel battery? Comparison of AGM and gel batteries

Both categorized as SLA (Sealed Lead-Acid) or VRLA (Valve Regulated Lead-Acid) batteries, the AGM (Absorbent Glass Mat) battery and the gel battery are often mistakenly considered the same thing. Both batteries have similar characteristics such as deep cycle capability, non-spillable design and the ability to operate in different orientations. These types of batteries are also known for their low self-discharge, easy maintenance and vibration resistance. However, AGM and gel batteries are two distinctly different types of batteries.

We will compare these two battery types to help you choose the one that best fits your application.

Comparison of technologies AGM vs Gel Battery

Similarities

These two batteries are classified as valve-regulated lead acid (VRLA) batteries. The oxygen produced on the positive plates of lead acid batteries is absorbed by the negative plates. In turn, the negative plates produce water. This allows the heat generated from the chemical reactions occurring in the electrolytes to be dissipated - the user does not need to control the amount of water in these batteries, making them maintenance free.

Differences

AGM batteries use a special glass mat consisting of thin glass fibers. Its function is to absorb electrolytes between the battery plates. AGM have a lower internal resistance, so they are able to work longer than gel batteries. Thanks to their design, they also have a larger capacity, which in the case of gel batteries is limited by the gel factor. These batteries are most often found in UPS units (cyclic operation).

Gel batteries use a special type of silica gel that holds the electrolytes together. The dense consistency of the material allows electrons to flow freely between the plates. Silica gel provides more efficient heat dissipation from the cells and a more secure, compact design that resists vibration and shock. In addition, these batteries are characterized by the ability to regenerate after the occurrence of prolonged short circuits and resistance to overcharging. The most commonly used battery technology in buffer power supplies.

Gel batteries tend to lose power faster than AGM batteries, especially at lower temperatures. This is because of the gel-based, thixotropic composition of the battery. AGM batteries perform well in extreme weather conditions, making them suitable for winter power-hungry devices such as snowmobiles.

When it comes to depth of discharge, gel batteries use acid better than AGM batteries. The acid protects the plates of gel batteries, making them more suitable for deep discharge. However, a gel battery must be charged properly or it will fail prematurely. Damage inside the gelatinous material can cause packs to form, which will corrode the plates.

AGM batteries are comparatively less expensive than gel batteries. However, the latter have a longer life span and offer more amperage when needed. These batteries are best suited for high-power applications such as sport utility vehicles.

Summary

AGM battery

• Preferred when current surge is required;
• Can last for years;
• Can be manufactured at a lower cost than a gel battery;
• Has lower internal resistance;
• Works well in temperatures below 32 degrees.

Gel battery

• Lower power capacity;
• Works well in a warm environment;
• Handles slow discharge well;
• Incorrect charging can damage the battery before it reaches the end of its life cycle;
• Not suitable for use as starter batteries due to increased acid resistance;

When deciding to buy a battery, there are several things to consider:

• What application will the battery be used for?
• Will the battery need to operate in sub-zero temperatures?
• How the battery will be charged?
• Do you need a slow discharge rate or sudden spikes in power?

Once you have the answers to these questions, you will be able to choose the best battery for your application. Warmer climates and lower discharge rates? A gel battery may be a good option. Cooler climates and using the battery as a starter battery? Definitely an AGM.