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Best AGM Car Batteries: Our 2018 Guide and Reviews

best agm car batteries

You want a battery for your vehicle that will last and offer reliability in cranking up each time you turn the key. We’ve reviewed the best AGM car batteries for your vehicle. Our guide will show you what to look for. First, let’s learn a bit more about car batteries.


Car Batteries – The Basics

Car batteries have two terminals – one positive and one negative. These are connected to the vehicle and send a steady flow of electrons, which power the radio, the A/C, the headlights, and most importantly, the engine starter.

Inside the battery, there are several energy-producing units known as cells. Each one has a couple of electrode sets and is made of overlapping plates. Together, these plates form a compact grid. The bigger the grid, the larger the surface and the more power it can generate.

A positive grid is covered in lead oxide and carries electrons. The negative grid releases electrons and is covered in lead.

Plates are soaked in a chemical bath composed of 65% water and 35% sulfuric acid, which is called an electrolyte and conducts electricity. As the battery discharges, chemicals on the plates react with the electrolyte. This releases electrons, and when they start running through the grids, they create electricity.

As electrons pass from the positive grid in the first cell and leave through the negative grid, they produce two volts of electricity. Then this process is repeated in the next cell, providing another two volts. Once the electrons reach the sixth cell, they have produced a combined voltage of 12. This is enough to power the car starter and crank the engine.

Once the motor starts, the fuel system takes over to keep the car running. That’s when the alternator helps the battery recover the energy spent. The chemical reactions are now reversed and electrons enter the battery through the negative grid of the cells and come out through the positive side. The chemicals on the grids get back to normal and the battery is recharged. That is, as long as you don’t turn off your car and leave the lights on. This will cause the electrons to go out, but never have a chance to go back in, so the battery is drained.


Best AGM Car Batteries: Our Top Pick

AMG Car Battery NameQualityPriceRating
Bosch S6585B S6 Flat Plate AGM BatteryA+$$
Exide Edge FP-AGM24F Flat Plate AGM BatteryA$$
Odyssey PC680 BatteryA+$
Optima Batteries 8020-164 35 RedTop Starting BatteryA$$
ACDelco 94RAGM Professional AGM BatteryA+$$

When should I replace a Car Battery?

Modern car batteries are designed to last for several years. Some are recommended to be replaced after 4 or 5 years, and some can last even longer. However, several warning signs can indicate that your battery is reaching its limit and should be replaced soon.

The main one is a slow engine crank. If you try to start your car and notice the engine is sluggish and taking longer than normal to start, you should check your battery as soon as possible.

Other warning signs are swelling or bloating of the battery case and battery leaks. Battery leaks can be detected by a stinky odor, similar to rotten eggs, or by corrosion around the negative and positive posts. Also, if your check-engine light turns on and you can’t see anything wrong with your car, it could be a faulty battery.

Short trips mean a shorter battery life. If most of your car trips take less than 20 minutes, your car battery won’t be able to recharge fully and its overall life expectancy will shorten.

TIP: It may be necessary to use a suitable charger to fully charge the battery – here you will learn more about how to charge and what charger to use.


What types of car batteries are there?

  • Lithium Ion Batteries for Car

    These batteries are lighter and provide better fuel efficiency. They are used primarily in electric vehicles and high-performance cars. For example, Porsche has used lithium ion batteries in some of their cars to start the engine. The main disadvantage of this type of battery is the price; they can be very expensive.

  • Flooded Auto Batteries

    This is the most common type of battery and can be either sealed or conventional. Sealed flooded batteries are maintenance free, while conventional batteries require you to regularly verify the electrolyte level and having to add distilled water if it is low.

  • Gel Car Batteries

    Gel batteries work in a similar way as flooded batteries, but instead of using water for the electrolyte, they use a gel similar to Jell-O. This keeps the battery from leaking if it gets cracked.

  • AMG Car Batteries

    Absorbed Glass Mat (AGM) batteries use fiberglass to keep the electrolyte between the plates. This allows them to be placed in any position, even upside down, and makes them very efficient. They last longer than conventional or gel batteries and resist freezing.


How should I choose a car battery?

As with many other replacement parts for your car, you should always check your vehicle’s owner’s manual to find out any specific requirements. Batteries are available in a wide range of prices, so, first of all, you need to set a budget. Your kind of driving is also important; if you frequently transit through off-road areas, you will need one with a durable casing.

Make sure the battery will fit in your car, and make sure it is fresh. Even while stored, batteries will lose strength over time, so you should not purchase one that is more than 6-months old. Most batteries have a shipping code on the case or on a label. Some use a letter for the month and a number for the year, while others use a numeric date.

A good warranty is something you should keep in mind while selecting your battery. Warranties usually offer a free replacement period and a prorated period, where you will only receive a partial refund. There is a code on batteries that let you check this. For example, if it says 12,48 it means that it can be replaced for free in the first 12 months, and then you have a prorated period of 48 months.


The Best AGM Car Batteries

Battery NameQualityPriceRating
Bosch S6585B S6 Flat Plate AGM BatteryA+$$
Exide Edge FP-AGM24F Flat Plate AGM BatteryA$$
Odyssey PC680 BatteryA+$
Optima Batteries 8020-164 35 RedTop Starting BatteryA$$
ACDelco 94RAGM Professional AGM BatteryA+$$

Bosch S6585B S6 Flat Plate AGM Battery

Bosch S6585B S6 Flat Plate AGM Battery-5be9f66fe1b22

Bosch is one of the largest suppliers of automotive components in the world. About 60% of their worldwide annual sales are produced in automotive technology, so you can be sure that this brand means quality.

The Bosch S6585B S6 Flat Plate AGM Battery uses what Bosch calls “Energy Life” technology. This provides up to 2 times longer life when compared to other conventional batteries. It is entirely sealed and 100% leakproof under any position you install it. Thanks to its Absorbent Glass Mat technology it can start the engine even in extreme hot and cold climates.

Pros

  • 4-year free replacement warranty included
  • Enhanced charge acceptance for faster recharging
  • Maintenance free
  • High vibration resistance

Cons

  • With a shipping weight of 58.38 pounds, it is heavier than many similar batteries

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Exide Edge FP-AGM24F Flat Plate AGM Sealed Automotive Battery

Exide Edge FP-AGM24F Flat Plate AGM Sealed Automotive Battery-5be9f671a7523

The Exide Edge FP-AGM24F Flat Plate AGM Sealed Automotive Battery is made with Surelife Graphite Technology which maximizes available energy capacity and makes it recharge faster. The internal components are held in place with fine-glass fiber mats and are engineered with a specially designed alloy that resists corrosion and maximizes battery life.

The battery is spill-proof, easy to install, even on its side, and has a recessed handle for quick installation and removal.

Pros

  • Maintenance free
  • Outperforms conventional batteries
  • High cranking power. Rated at 710 cold cranking amps (CCA)

Cons

  • Expensive

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Odyssey PC680 Battery

Odyssey PC680 Battery-5be9f673348ca

The Odyssey PC680 Battery delivers enormous crank power as well as deep-cycle reserve power. Even at low temperatures, it can produce double-to-triple the power than equally sized conventional batteries. Its flat plates are made of 99.9% pure lead instead of lead alloy; this allows the plates to be thinner and more of them can be fitted with the battery. More plates mean more surface area, and that translates into more power.

This battery has a fast recharge rate, capable of a 100% recharge in 4 to 6 hours. It has a vibration-resistant design and high heat tolerance. If you are looking for a battery replacement for your ATV, snowmobile, or even your ultralight aircraft, this should be a good option to consider.

Pros

  • 3-10 years of service life expected
  • Non-spill design
  • Good solid build

Cons

  • Only offers a limited 2-year full replacement warranty, not pro rata

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Optima Batteries 8020-164 35 RedTop Starting Battery

Optima Batteries 8020-164 35 RedTop Starting Battery-5be9f6751dd2d

The Optima Batteries 8020-164 35 RedTop Starting Battery is designed to deliver an intense burst of ignition power for a reliable startup every time, thanks to its 720 cold cranking amps. This is a battery that hot rod and off-roaders like as it can withstand any heavy use.

A feature that makes the Optima an excellent option to consider is that it uses a spiral cell technology; these are a series of individual spiral-wound cell that that let the battery deliver more power and consistently outperform most conventional flat-plate batteries. It has a reserve capacity of 90 minutes, and its optimal starting power won’t be affected by inclement weather.

Pros

  • Easy to install
  • Users have reported using it at -20°F temperatures and having no issues getting their engine started
  • Good cranking power

Cons

  • Pricier than similar batteries

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ACDelco 94RAGM Professional AGM Automotive BCI Group 94R Battery

ACDelco 94RAGM Professional AGM Automotive BCI Group 94R Battery-5be9f676c123a

The ACDelco 94RAGM Professional AGM Automotive BCI Group 94R Battery is maintenance free and tested against leaks, thanks to its AGM technology. This absorbed glass mat design means that the electrolyte doesn’t flow within each cell and instead is held in the glass mat separator, so there is no way for it to leak or spill.

This battery uses a calcium lead positive grid, which allows for lower resistance and maximizes conductivity, and has a vent cap design that resists acid leakage. Integral gas separators and flame arrestor vents prevent possible damage from outside sparks.

Pros

  • Improved acid circulation helps the battery to remain cool
  • 36-month free replacement warranty
  • High cycling capability

Cons

  • Some users have reported having a tough time starting their engines in cold weather

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Conclusion

The Bosch S6585B S6 Flat Plate AGM Battery should be the first option to consider when searching for the best AMG car batterry. The AGM technology means that the electrolyte does not flow freely in the case as it does in standard flooded-cell batteries, so it is totally leak proof. It is a battery that can hold up to the high-powered demands from heating seats, GPS navigation systems and onboard computers.

An extra feature that might get you out of a predicament is the Bosch Roadside Assistance program provided via Auto Road Services that comes with this battery. And the warranty is top-notch, offering a 4-year free replacement.