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Can I Replace an EFB Battery with an AGM Battery?

Power - by Bryan Veldboom - updated on 3/22/2022

reconnecting a battery

Cars and trucks today have more technology onboard than ever before. In order to keep up with the power demands of these new bells and whistles, many modern vehicles require a more powerful type of battery. This is especially true for vehicles that feature start-stop technology. If you have a vehicle with a start-stop system, you'll need one of two different battery options: EFB or AGM. Today, we'll break down the differences between EFB and AGM batteries and tell you which one performs the best.

What are EFB Batteries?

EFB stands for Enhanced Flooded Battery. As their name suggests, EFBs offer a number of advantages over traditional flooded lead acid auto batteries. This is due to the use of a special poly fleece material lining each of the battery's vertical plates, which allows for a more consistent flow of power.

EFBs also have thicker plates which allow them to be discharged much deeper than traditional vehicle batteries. An EFB will stand up to the larger number of cycles required by a start-stop system, while still providing the power needed to run things like lights, radios and your AC. They also tend to have slightly longer lifespans. A typical auto battery will last between three and five years, while an EFB can last as long as six years.

What are AGM Batteries?

AGM (short for Absorbed Glass Mat) batteries are constructed differently than other vehicle batteries. While both flooded batteries and EFBs contain a series of plates immersed in a free-flowing liquid electrolyte, AGM batteries keep their electrolyte suspended in a series of fiberglass separators that sit between the battery's plates. Due to this design, AGM batteries are completely sealed, making them leakproof and maintenance-free. They also have a lower internal resistance, giving them a higher voltage output and a much shorter charging time.

What are the Advantages and Disadvantages of AGM Batteries?

While EFBs are an improvement over traditional flooded auto batteries, AGM batteries outperform enhanced flooded batteries. For starters, AGM batteries provide more electrical energy than an EFB can and recharge up to five times faster. An AGM battery will also typically last two to three times longer than a flooded battery, with an average lifespan of five to eight years. Plus, they're much better at standing up to the negative impact of vibrations and extreme weather. On the downside, an AGM battery will cost you more upfront than an EFB, however, since they last longer, an AGM battery will probably end up saving you money in the long run. In addition, AGM batteries have much longer warranties.

EFB or AGM - Which Battery Do I Need?

If your vehicle currently has an enhanced flooded battery under the hood, it's perfectly fine to upgrade it to an AGM. Many drivers who live in cold climates will purchase AGM replacements because they're more reliable in winter. If your vehicle's original battery was an AGM battery, however, you should not swap it for an EFB. Downgrading your battery can cause issues with your vehicle's start-stop system and reduce the battery's overall life.

Where Can You Buy AGM Batteries?

Batteries Plus features an enormous selection of batteries for your car or truck. Visit our Battery Buying Guide for a closer look at some of our most popular brands, including our top-performing brand X2Power. If you'd like to know more about AGM batteries, we have plenty of helpful topics in our blog. Some suggested topics include "What is an AGM battery?" and "How Do AGM Batteries Perform in Cold Weather?"

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