Difference between EFB and AGM batteries
Construction:
- EFB: EFB batteries have a standard lead-acid construction with a special absorbent glass mat (AGM) separator that is treated with a proprietary material. This treatment enhances the separator's ability to absorb and retain electrolyte, improving cycle life and vibration resistance.
- AGM: AGM batteries also use an AGM separator, but it's typically not treated with the same proprietary material as EFB batteries. The AGM separator in AGM batteries is designed to absorb and retain electrolyte more effectively than standard lead-acid batteries, preventing electrolyte leakage and improving performance.
Applications:
- EFB: EFB batteries are generally designed for vehicles with moderate electrical demands, such as those with stop-start technology, advanced audio systems, or electric power steering. They offer a good balance of performance, reliability, and cost.
- AGM: AGM batteries are typically used in vehicles with higher electrical demands, such as those with advanced start-stop systems, regenerative braking, or large infotainment systems. They provide superior performance, longer cycle life, and better resistance to vibration compared to EFB batteries.
Performance:
- Cycle life: Both EFB and AGM batteries offer improved cycle life compared to standard lead-acid batteries. However, AGM batteries generally have a slightly longer cycle life due to their enhanced electrolyte retention capabilities.
- Vibration resistance: Both EFB and AGM batteries are more resistant to vibration than standard lead-acid batteries. However, AGM batteries may have a slight edge in this regard due to their superior electrolyte retention.
- Cold cranking amperage (CCA): Both EFB and AGM batteries can have high CCA ratings, making them suitable for cold weather starts. However, AGM batteries may have slightly higher CCA ratings in some cases.
Cost:
- Price: AGM batteries typically cost more than EFB batteries due to their more advanced construction and superior performance.
In summary:
- EFB batteries are a good choice for vehicles with moderate electrical demands. They offer a balance of performance, reliability, and cost.
- AGM batteries are ideal for vehicles with higher electrical demands. They provide superior performance, longer cycle life, and better resistance to vibration, but they are generally more expensive than EFB batteries.