Duralast EFB vs AGM Battery

The main difference between the Duralast EFB and Duralast AGM batteries is the battery technology. The Duralast EFB uses Enhanced Flooded Battery (EFB) technology, while the Duralast AGM uses Absorbed Glass Mat (AGM) battery technology.

Duralast EFB vs AGM

This table of comparison will allow you to easily grasp the differences.

Feature Duralast AGM Duralast EFB
Battery Technology Absorbent Glass Mat (AGM) Enhanced Flooded Battery (EFB)
Warranty 3 years 3 years
BCI Group Size 48 48
Cold Cranking Amperage 760A 750A
Cranking Amperage 950A 935A
Reserve Capacity 130 mins 120 mins
Price $249.99 $249.99
Terminal Type SAE – Type A SAE – Type A
Negative Terminal Location Top Left Top Left
Positive Terminal Location Top Right Top Right
Length 11.0 in 6.88 in
Width 6.94 in 11 in
Height 7.5 in 7.5 in
Weight 46.9 lbs 42.12 lbs
Voltage 12V 12V

Battery Technology

The Duralast EFB battery utilizes Enhanced Flooded Battery technology. This means it is a lead-acid battery with a liquid electrolyte like a conventional flooded battery. 

However, Duralast EFB batteries include modifications like a carbon additive and reinforced grids to improve performance compared to standard flooded batteries. The carbon additive enables faster recharging and increased battery life.

The Duralast AGM battery uses Absorbed Glass Mat technology. AGM batteries are also lead-acid, but the electrolyte is held in absorbent glass mats between the plates rather than liquid. 

This makes AGM batteries spill-proof and allows them to be installed in different orientations. AGM batteries generally provide higher cycle life compared to flooded batteries.


The Duralast EFB and Duralast AGM batteries come with a 3-year free replacement warranty, providing peace of mind with the purchase. This covers defects in materials and workmanship.

Group Size

The Duralast EFB has an EN group size of LN3 and a DIN group size of H6. The Duralast AGM does not specify an EN group size but has the same DIN group size of H6. Both use the standard BCI group size of 48.

This means the batteries are interchangeable in most applications requiring a group 48 battery.

Cold Cranking Amps

The Duralast AGM battery provides a higher cold cranking amp (CCA) rating of 760A versus 750A for the Duralast EFB. The higher CCA enables better starting power in cold weather.

Cranking Amps

For starting power at room temperature, the Duralast AGM is rated at 950A cranking amps compared to 935A for the Duralast EFB. Again, the AGM has a slight edge.

Reserve Capacity

The Duralast AGM also bests the Duralast EFB in a reserve capacity, with 130 minutes versus 120 minutes, respectively. This indicates the AGM can deliver a usable charge for longer if the alternator fails.


Both the Duralast EFB and AGM batteries retail at the same price point of $249.99. Shoppers get premium performance at a competitive price point with either option.

Terminal Location

The batteries share a standard design with side terminal locations. The positive terminal is located on the top right, and the negative terminal is located on the top left for both models.


The batteries do differ slightly in their dimensions:

  • Duralast AGM: 11.0 x 6.94 x 7.5 inches
  • Duralast EFB: 6.88 x 11 x 7.5 inches

So, the AGM battery has a more extended, narrower footprint compared to the shorter, wider Duralast EFB.


The AGM battery is heavier at 46.9 pounds versus 42.2 pounds for the Duralast EFB. This minor difference is likely due to additional materials in the AGM construction.


Both batteries have a voltage rating of 12V, which is the standard for most passenger vehicles. This voltage rating ensures seamless integration and replacement in existing 12V systems.

Additional Features

The Duralast AGM highlights its non-spillable design for safer, maintenance-free operation given the absorbed electrolyte. It also emphasizes superior performance in hot and cold weather conditions.

The Duralast EFB promotes its faster recharging capabilities and increased cycle life thanks to its carbon additive. Its reinforced grids also help extend service life by resisting corrosion.

Our Observation
The Duralast Platinum AGM Battery offers slightly higher cold cranking amps (760A vs. 750A) and longer reserve capacity (130min vs 120min), making it better for vehicles demanding more starting power in cold weather.

However, the Duralast EFB battery has a higher amp hour rating (74Ah vs 70Ah), and its carbon additive enables faster recharging. Given Duralast EFB’s compatibility with more vehicles designed for conventional batteries.

We recommend the Duralast Platinum EFB as the best overall choice for most drivers needing a replacement battery.

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