Duralast vs Diehard AGM

Both are similar in many aspects like battery technology, warranty period, voltage, dimensions, and cold cranking amps. However, Duralast is cheaper, while DieHard offers slightly better reserve capacity and unique stamped grid technology for improved durability.

Duralast vs Diehard

This table is designed to make it easier for you to understand the differences quickly and efficiently.

Feature Duralast DieHard
Price $249.99 $276.99
Battery Technology AGM AGM
Warranty 3 years 3 years
Group Size BCI 48 H6
Cold Cranking Amps 760 760
Cranking Amps 950 950
Reserve Capacity 130 min 120 min
Terminal Type SAE – Type A Top Mount
Dimensions 7.5 x 6.94 x 11 in 7.5 x 6.937 x 11 in
Weight 46.9 lbs 45.6 lbs
Voltage 12V 12V
Key Features Cycle life, fast recharging, start-stop ready Stamped grid, corrosion resistance

Battery Technology

Both Duralast and Diehard offer absorbent glass mat (AGM) battery technology. AGM batteries use fiberglass mats to absorb and immobilize the battery’s electrolyte fluid.

This makes them spill-proof and allows them to be installed in any orientation without leaking. AGM batteries also charge faster, have a longer service life, and perform better in cold weather compared to standard flooded batteries. The sealed AGM design prevents corrosion and gassing.


Duralast Platinum AGM batteries come with a 3-year free replacement warranty. DieHard offers a 3 year free replacement warranty on their Platinum AGM batteries as well. So both brands provide the same generous replacement coverage in case of defects.

Group Size

Duralast uses the BCI Group Size 48 classification. DieHard utilizes the H6 group size designation for their Platinum AGM offering. While the group size codes differ, the physical dimensions of the two batteries are very close.

Cold Cranking Amperage

The cold cranking amperage (CCA) rating measures a battery’s ability to start an engine in cold temperatures. Both the Duralast and DieHard Platinum AGMs have an impressive 760 CCA rating. This high output ensures reliable starting power even in frigid winter conditions.

Cranking Amperage

In addition to identical CCA ratings, the two batteries also share the same 950 cranking amperage (CA) rating. This measures starting power at 32°F. The high CA of 950 amps will provide fast, strong engine cranking in cool weather.

Reserve Capacity

The DieHard Platinum has a reserve capacity of 120 minutes, while the Duralast Platinum beats it slightly with a 130 minute reserve capacity.

This refers to the length of time a battery can deliver 25 amps while maintaining a voltage above 10.5 volts. The higher 130 minute rating gives the Duralast a slight edge.


The Duralast Platinum AGM costs $249.99, which makes it around $27 cheaper than the $276.99 DieHard Platinum. This cost saving gives the Duralast an advantage in terms of value.

Terminal Location

The DieHard uses a top mount terminal configuration with positive on the right and negative on the left. The Duralast has an SAE top terminal pattern with positive also on the right when viewing the battery from above.


As mentioned earlier, the physical dimensions of the two AGM batteries are very similar. Both measure 7.5 inches tall.

The DieHard is 11 inches long and 6.937 inches wide. The Duralast comes in at an almost identical 11 inches long and 6.94 inches wide.


At 45.6 pounds, the DieHard AGM is slightly lighter than the Duralast which weighs 46.9 pounds. This 1.3 pound difference is negligible and both models are reasonably lightweight given their high power output.


The standard 12V voltage is consistent between the DieHard and Duralast Platinum AGM batteries. This is the typical voltage used for most automotive starting, lighting, and ignition (SLI) applications.

Additional Features

An advantage of the DieHard Platimum AGM battery is its stamped grid technology which enhances durability and corrosion resistance for longer life.

The Duralast highlights its spill-proof design and suitability for vehicles with start-stop systems and multiple electronics drawing higher power. Both offer robust vibration resistance as well.

The Bottom Line
Either the Duralast or DieHard AGM batteries represent a high-quality choice. With the same 760 CCA rating, three year warranty, and nearly identical size, the two batteries offer comparable performance.

The DieHard touts improved durability from its grid design. Still, for most drivers, the more affordable Duralast is likely the better option.

Given the significant price difference of around $25, we recommend the Duralast Platinum AGM battery for value-conscious drivers who want proven AGM technology without paying a premium.

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