Difference between AGM Battery and Lead Acid Battery

It’s most likely concerning 10 years since the primary Stop-Start vehicles became production vehicles. Consequently, the batteries for these vehicles are currently requiring dynamical. Motorists with these Start-Stop vehicles became terribly confused as regards to that battery to exchange their previous batteries. Confusion surrounds the two new technology automobile batteries that were originally fitted to those vehicles, which are the deep cycle AGM battery and therefore the EFB Batteries.

However, I‘ll try and justify the distinction and conjointly the right fitments for your car/van. Thanks to environmental problems then there are currently quite seventieth of recent cars that are equipped with an Associate in Nursing energy saving Start-Stop system. Automobile makers developed this method together with battery makers. So, the Start-Stop system allows the vehicle to change off the engine once the vehicle involves a halt! Say at traffic lights and get road junctions.

How AGM battery VS Lead Acid Battery Work

The AGM battery and therefore the commonplace lead acid battery is technically identical once it involves their base chemistry. They both use lead plates and an electrolyte mix of sulfuric acid and water and have a chemical reaction that produces hydrogen and oxygen as a byproduct.

However, this can be once they begin to diverge. Here’s how:

Flooded Lead Acid Battery

The flooded lead acid battery (FLA battery) uses lead plates submerged in a liquid solution. The gases made throughout its chemical process are ventilated into the atmosphere, inflicting some water loss. Thanks to this, the solution levels would like regular renewal.

AGM Battery

The AGM battery uses AGM mats sandwiched between lead plates. It’s wherever the battery gets its name – Absorbent Glass Mat (AGM). The glass mat wicks the solution resolution, keeping it suspended in situ, therefore it’s not free-flowing. Because the AGM leisure battery could be a sealed battery, there’s a token to no off-gassing. Gases made throughout the chemical process recombined with the solution. And if there’s excess gas (such as once the battery is overcharged), a vent releases it to keep up internal pressure.

AGM separator in battery

Maintenance Requirements

The AGM battery is maintenance-free and may be placed in additional b areas as there’s no off-gassing aside from the occasional emission. It’s fitted to use in vehicles with batteries in trunks and beneath seats or in locations wherever maintenance may be onerous to try and do. On the opposite hand, the flooded battery needs regular solution conjugation and wishes to be in a well-ventilated space because it releases gases and steam.

Durability, Vibration and Shock Resistance

The AGM battery tends to be designed tougher than the flooded lead acid battery because it originally served military and aviation use.

The sandwiched configuration of glass mat and battery plates within the deep cycle battery interprets parts that don’t fall aside simply. This structure leads to A battery that’s shock and vibration-resistant — creating them favorites in race cars and motorcycles. Forceful movements and significant vibrations will injure flooded battery plates, and they got to be mounted firmly to reduce these effects.

Mounting Flexibility and Spillage

The glass mat technology within the AGM battery makes it spill-proof and position insensitive. You’ll be able to mount it in several configurations (just don’t flip it side down). However, the flooded cell battery has a liquid electrolyte, therefore it should be upright to stop spills. The spilled solution will cause corrosion if not cleaned up.

Car battery leakage

Internal Resistance and Power Output

The AGM battery’s internal resistance is at an all-time low for assorted lead acid batteries. Whereas a replacement flooded lead acid battery will have an inside resistance of 10-15%, a replacement AGM battery may be as low as two. Low internal resistance interprets to multiply battery voltage output. It conjointly suggests a reduced loss of warmth as power circulates within the system.

Deep cycle batteries conjointly reply to loading higher than flooded lead acid or gel batteries. They handle giant power demands therefore well that they’re the go-to lead acid selection for start-stop vehicles.

Charging Time

Low internal resistance conjointly grants the AGM battery quicker charging times. Not as quick as lithium batteries, however up to 5x quite a flooded lead acid battery, once mistreatment identical power supply.

Depth of Discharge

AGM batteries have an 80% depth of discharge (DoD), which is healthier than the five hundred United States Department of Defense offered by a flooded cell battery. This makes the AGM 12v gel battery well-suited to deep cycle applications.

Even so, it’s not counseled to discharge either battery kind below five hundredths of its capability — not like the lithium battery, which might be absolutely discharged. Depth of Discharge indicates what quantity of battery capability may be discharged safely while not damaging it.

DOD of AGM battery

How do you tell if battery is an AGM

Your AGM battery is not really dead!

Find a known good battery and connect it to the charger.

Take your bad AGM battery (which really isn’t bad) and connect it with alligator clip jumpers in parallel with the good battery.

Allow it to charge at a low rate..2 amps or less for a few hours. The charger ‘reads the first battery as good. and will allow itself to charge it 

What is the best AGM battery to buy

Best AGM Battery: Capacity, Deep Cycle Power, Reserve Capacity, Voltage, CCA | Trusted Brands

Customers’ Choice. 12V 120AH SuperBatt DT120 Heavy Duty Ultra Deep Cycle Dual Purpose Leisure Marine Battery with Dual Terminals.

Best Value.

Most Popular

Best Budget.

Most Discussed & Reviewed.

Best Trusted.

Best Cheap

Other Popular AGM Batteries


When comparing the AGM battery and lead acid battery, you’ll notice that they need a large number of variations. However, there’s one very little issue to stay in mind:

If your original battery is a 100ah AGM battery, you can’t modify it to an FLA battery. The flooded battery merely won’t have enough juice to fulfill all of your car’s power demands.

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