Battery 101: AGM vs GEL Batteries Leave a comment

What is the difference between AGM and GEL Battery technology?

AGM Batteries

AGM stands for Absorbent Glass Mat.  The absorbent glass mat refers to a fine fibreglass mat that is capable of absorbing sulfuric acid, making batteries spill-proof.

In the 1980’s the demand was increasing for lighter weight and less hazardous batteries that could be used in aircraft and vehicles. AGM Battery technology allowed this demand to be met. Suddenly batteries could be transported without hazardous material issues and the construction of the mat meant that batteries could now be shaped as a cylinder or the traditional rectangular cube.

GEL Batteries

GEL Battery technology is another matter altogether.

A gel cell battery is a battery that uses a sulfuric acid that has been mixed with fumed silica to create a gel-like substance that is immobile. Because of the GEL cell, the battery does not have to be kept upright and the electrons can flow between the plates without the threat of spilling.

Gel batteries produce few fumes which make them ideal to be used in places that don’t have good ventilation.

The Differences between AGM & GEL Batteries

The similarities between AGM & Gel Batteries can cause people to confuse the two technologies. Both are on-spillable, both are deep cycle (meaning they can be deeply discharged), and both can be transported safely among other things. So what sets them apart?

AGM Batteries

  • Perform well when a burst of amps is often required.
  • Can last for years.
  • Can be easily recharged, in some cases up to 5 times faster.
  • Can be produced at a lower cost than gel batteries.
  • Have a low internal resistance.
  • Perform well in temperatures below 32 degrees.

GEL Batteries

  • Lower power capacity.
  • Does well in warmer environments.
  • Does well with slow discharge rates.
  • If recharged incorrectly the battery will fail before the end of its life cycle.
  • Not suitable to be used as starter batteries because of increased acid resistance.
  • Do not perform well in below-freezing temperatures.

When trying to decide which battery to purchase consider a few things.

What application are you using the battery for?
Will the battery have to function in below-freezing temperatures?
How will you recharge the battery?
Do you need a slow discharge rate or will you require bursts of power?

In warmer climates with applications where lower discharge rates are required Gel Batteries will do better.

In colder climates with applications where a frequent burst of amps are requred, AGM batteries will be better suited.

Understanding the battery you are purchasing will go a long way in preventing damage to your equipment and preserving the life of the battery.


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