What Is An AGM ? AGM Battery Vs. Lead Acid Battery

What Is An AGM Battery? 

VRLA battery (Valve regulated lead-acid) is commonly referred to as sealed lead-acid batteries and are lead-acid based rechargeable batteries that require little to no maintenance. A common feature of this type of battery is as the name implies, they are always manufactured to be a sealed battery with a built-in safety pressure relief valve. If the sealed lead acid battery were ever to be inverted or in any other position than upright, the battery is incapable of leaking and cannot spill its electrolyte (battery acid). Also, when the typical lead-acid based battery is recharged at a mild to high voltage, it will emit gases that can be considered dangerous if emitted in large quantities.

Since the VRLA battery is sealed, when the battery is put on charge, it relies on its built-in pressure release valve to alleviate the pressure from the gases which build up inside the battery. The release valve emits small trace amounts of these gases. It has enabled any VRLA battery to be placed in small units (such as battery backup systems) inside buildings or offices without worrying about harmful gasses being emitted. These batteries are further divided into two subgroups know as absorbed glass mat (AGM) batteries and the gel battery.

The AGM battery differs from other lead-acid batteries because it uses a glass mat separator to hold its electrolytes in place. These mats allow for the AGM battery to accumulate the highest frequency of acid available and never spill a drop. It was developed in the 1980s by Concorde Aircraft battery, and they intended to create warm weather, vibration resistant, a chemical alternative to the current expensive batteries being used in their fighter air-craft technology. Today the AGM is applied in motorcycles as well as many automobiles. They are also frequently used in remote sensors and cold environments due to their lack of free electrolyte they will never corrode or crack.

Pros to the AGM Battery

1. They have low internal resistance allowing then to be charged and discharged rapidly.

2. They are maintenance-free.

3. Will not corrode their surroundings because the acid is trapped in the matting.

4. Handle vibration very well.

Cons of the AGM battery

1. A tad expensive being nearly double the price of a flooded cell battery.

2. They don’t accept overcharging as it burns the electrolyte, which is irreplaceable in the AGM model.

Finally, the Gel battery, sometimes called the gel cell, is unique due to its utilization of qualified electrolyte. The gel is created by sulfuric acid mixed with silica fume, causing it to become an immobile gel mass. The gel cells are almost extensively used in power wheelchairs because of their extensive deep-cycle capabilities and low acid output. Both types of VRLA batteries are widely used in aerobatic aircraft due to their knack for withstanding various flight altitudes and their large ambient temperature range.

An AGM battery is an advanced lead acid technology that provides a longer life span, higher electrical loads, higher cranking amps, quick recharge time and an extended cycle life. 

The technology and design of AGM batteries makes them spill proof, maintenance free, and vibration resistant. 

They perform well in rough climates and demanding conditions and this makes them perfect for start and stop applications and provides greater mounting flexibility. 

AGM stands for Absorbed Glass Mat. 

The Absorbed Glass Mat absorbs the electrolytes (acid) and stores it in a “dry” state, which prevents the liquid from moving around, unlike the free form liquid in a standard lead acid battery. 

The difference between AGM and Standard Lead Acid Batteries is how they are composed. 

How A Stand Lead Acid Battery Composed (see below):

There’s a positive and negative plate with a porous separator in between. This form an element, an element produces 2 volts and a cell is composed of several elements and to make a 12 volt battery you need 6 cells and that is what produces a standard 12 volt battery. 

positive plate → porous separator → negative plate → electrolytes (acid)

How an AGM Battery is composed (see below):

An AGM battery has the same principle as the Lead Acid Battery but is designed more efficiently and because of that it withstands more vibration and is able to produce more cranking power within the same space. 

The similarity is that each cell is going to produce 2 volts. 

The difference is that each cell is designed differently. 

There’s a positive lead grid, there’s a positive plate, then you have a positive plate with a micro glass fleece that absorbs the electrolytes, then you have a negative grid, and a negative plate. 

These are all compressed together and you need several of these to compose a cell. It takes 6 of these cells to produce 12 volts. 

positive lead grid → positive plate → positive plate with a micro glass fleece that absorbs the electrolytes → negative grid → negative plate.

As you can see from the above diagrams, the difference is in the advanced design of AGM batteries. 

The history of AGM batteries goes back to the 1970’s as back power for telephone boxes and computers and in 1980’s they were initially used in military applications where power, safety, and reliability were top priority. Years later they were re-developed for civilian applications. 

The primary purpose of AGM batteries is to deliver a powerful burst of cranking amps and the ability to run electronics for a long period of time. 

At Brava Battery we recommend AGM batteries over standard lead acid batteries for your motorcycle, ATV, snowmobile, side by side, dirt bike, or other powersport vehicle because of the benefits: 

• Reliable

• Non-Spillable Sealed Design

• Repeated Charges and Discharges Without Diminished Performance

• Long-Lasting Performance Even In Demanding Applications

• Vibration Resistant

• Maintenance-Free

• Permanently sealed special absorbed-glass mat battery eliminates water loss. No need to add any liquid to the battery

• Holds charge three times longer than conventional batteries

• High performance active material with anti-sulfation additive

• High capacity and cranking performance

• Maintenance Free – No additional water needed

• Sealed Valve Regulated

• Spill and Leak Proof

• Deep discharge protection

• Plate grids from lead-calcium alloy, free of antimony

• Long Shelf – Charged and ready for use

• Excellent starting and cycling

• Installs in any position except upside down

What Makes A Brava Battery Different? 

We invented a specialized expert 5 step process to prepare each and every battery before it’s shipped to you. 

Here’s what we do to ensure the quality, performance, and lifespan of each AGM battery:

Step 1: Fill battery to the correct levels with 1.265 SG Electrolyte

Step 2: Let sit for 1 hr. so the Glass Mat plates are able to absorb the electrolytes properly.

Step 3: Charge battery at 1-2 amps until fully charged.

Step 4: Let sit for 12 hrs. and record voltage . Should maintain 12.6-12.8V.

Step 5: If it passes the voltage test, it’s ready to ship out to you.

Yes...This process takes more time and effort but that’s what makes our batteries different. It’s the reason our battery quality is superior!

Nobody in the industry does this and quite frankly, they might not know how to do it the right way. 

Brava Battery Ltd is a "true" expert battery shop. We have been performing specialized battery rejuvenation for over a decade...we know batteries!

95% of the suppliers or vendors out there that sell AGM batteries are not battery experts and that is why their batteries don't last!

The reason their batteries don’t last is because they are not filled properly and they are "fast" charged which basically damages the battery right from the start.

One of the most important things about a Brava Super Battery is our unbeatable warranty. 

You can choose between a 10 year warranty and 2 year warranty. 

The choice is completely up to you.