VRLA AGM Batteries

VRLA AGM batteries are one of the two main types of VRLA batteries.

AGM stands for Absorbed Glass Mat. It is a porous glass mat separator with the ability to absorb a large amount of electrolyte while still allowing some pores to be unfilled. These empty pores act as channels for oxygen to move from the +ve plate to the –ve plate (where hydrogen is released) and recombination to take place. That is why these batteries are called VRLA AGM batteries.

The main advantages of VRLA AGM batteries are:

  • They have the widest temperature range of all the lead acid battery types.
  • They have the lowest self-discharge rate of all the lead acid battery types.
  • They have the best shock/vibration resistance of all the battery types.
  • They have the bBest performance for high power applications.
  • They are less expensive than VRLA Gel batteries.

The main disadvantages of VRLA AGM batteries are:

  • They don’t perform as well as FLA or VRLA Gel batteries in regular deep discharge (>80% DOD) applications, which are increasingly required these days with the advent and popularity of solar applications.
  • They don’t perform as well as VRLA Gel batteries in low power applications.
  • They are more expensive than FLA batteries.

 

VRLA Gel Batteries

VRLA Gel batteries are one of the two main types of VRLA batteries.

VRLA Gel batteries use a composite separator made of a glass mat bonded to a porous polyethylene or polyvinylchloride sheet. The batteries are then filled with a thixotropic gel mixed with sulphuric acid. That is why they are called VRLA Gel batteries or T Gel batteries.

The main advantages of VRLA Gel batteries are:

  • They perform much better than VRLA AGM batteries in regular deep discharge (>80% DOD) applications.
  • They perform better than VRLA AGM batteries in low power applications.

The main disadvantages of VRLA Gel batteries are:

  • They have a higher self-discharge rate compared to VRLA AGM batteries.
  • They don’t perform as well as FLA or VRLA AGM batteries in cold temperatures (<40° F) since the gel freezes.
  • They don’t perform as well as FLA or VRLA AGM batteries when they regularly reach a shallow depth of discharge (<20% DOD).
  • They are more expensive than FLA and VRLA AGM batteries.