Everything you need to know about AGM and Gel batteries

When we enter the vast world of maintenance-free lead-acid batteries, the first decision we must make is whether we want an AGM battery or a Gel battery. In our article today we will learn about the characteristics of each of these batteries and why they are different from other types that we can get on the market, so that we can clarify a little the panorama around our final choice.

Everything you need to know about AGM and Gel batteries

Basically these types of batteries are those that belong to the group of sealed batteries, which are the same as the aerated ones considering the active materials and charge and discharge reactions. Despite this, there are certain characteristics that make them different.

One of these differences is that although it is true that sealed accumulators have the same electrolyte as aerated lead acid batteries, the big difference is that this electrolyte does not appear in liquid form, but rather is immobilized. Considering this particular difference, we could say that there are two types of sealed batteries, considering only the method used to immobilize the electrolyte.

Now we are going to explain the operation of AGM batteries and Gel batteries.

AGM battery

AGM batteries are VRLA (Valve Regulated Lead Acid) valve regulated acid batteries that are of the sealed, hermetic, maintenance free and immobilized electrolyte type.

AGM batteries are literally the evolution of gel batteries. Better known as absorbed electrolyte accumulators, or electrolyte in absorbent material or dry batteries, AGM (Absorption Glass Material) use plates that are correctly sandwiched between absorbent fiberglass meshes, 90% saturated with the electrolyte, remaining thus confined and diffusing into them by capillary action.

Even these fiberglass meshes that compose it provide a fairly firm support for the plates, which makes it one of the most resistant batteries to shock vibrations.

This type of constructive characteristics of AGM batteries gives it a series of qualities that stand out from the rest of the solar batteries. For example, its lower internal resistance translates into a higher ability to deliver and absorb current. Its characteristics also give AGM batteries the ability to be somewhat more resistant to deep discharge than GEL batteries.

Gel battery

Gel batteries are also VRLA (Valve Regulated Lead Acid) valve-regulated acid batteries that are of the sealed, hermetic, maintenance-free and immobilized electrolyte type.

In their case, these are manufactured from cells similar to those of liquid electrolyte batteries and the container that contains them is usually opaque. This electrolyte that composes them is a solution of sulfuric acid present in the form of a gel, as a result of the addition of a special silica.

At the time of charging these batteries, tiny cracks occur in the gel, opening the way for the recombination of gases released during gassing. Non-recombined gases could cause an increase in pressure inside the battery, for this reason, each of the cells has a pressure regulation valve, allowing the pressure generated by an excessive load to be relieved.

ts hermetic design and electrolyte immobilization in the gel structure make it possible for this battery to be placed in almost any position without risk of electrolyte loss. This makes them ideal for taking advantage of spaces intended for service batteries in caravans, boats and other vehicles that incorporate one or more service batteries.

And now… AGM or GEL?

Without a doubt, everything will depend on our project and of course, on our budget. Our choice should always be based on our needs for the proper functioning of our solar energy system.

As you have already seen, the differences between the two types of batteries are not that many and therefore on many occasions the decision of the battery to install between AGM and GEL will be more than anything based on capacity (Ah) and price, since at equal qualities of batteries, the results that we will obtain with one or another battery will be very similar. Of course, there are many different qualities of batteries on the market and a better quality will always give us a longer battery life, so there are times when investing a little more in a quality battery, it will do that in the long run. It’s much cheaper for us.

You can take a look at our section of solar batteries and see the AGM and GEL that we have. You can also contact our ecofener customer service department directly to advise you and we will guide you in everything you need.