EFB vs AGM: Which battery is best for your car?

Date: January 18, 2024

Due to the growth of start-stop engines, nearly all newly produced vehicles will need either an EFB or a higher-performance AGM battery. Many people are curious if they can trade these batteries in for EFB batteries that are more budget-friendly. Understanding the difference between these battery types will aid in selecting the most suitable one for your vehicle.

Continue reading to ensure you choose the best option for powering your car.

AGM Batteries


AGM batteries fall under the category of deep-cycle batteries. These are sealed and require no maintenance. What sets AGM batteries apart from other deep cycle batteries is their incorporation of Absorbed Glass Mat (AGM) technology. Consider this an advanced gel battery design that reduces electrolyte loss compared to conventional flooded lead-acid designs. The efficiency of your AGM battery is enhanced by its sealed design. When compared to other batteries, this type offers a longer lifespan.

Charging of AGM Batteries

The charging process for AGM batteries involves a steady, low current. They can be charged by a battery charger that has AGM mode enabled. The charger will continue charging until it reaches around 14.6 volts, or until it reaches the manufacturer's recommended energy level. Afterward, the charging device will ensure that this level is maintained. The AGM battery's operation relies heavily on this type of low-current charging. AGM batteries can be harmed if they are overcharged or discharged excessively.

Advantages of AGM Batteries

These batteries have a long-lasting lifespan. Deep discharge cycles can double the lifespan of AGM batteries compared to conventional batteries. Additionally, they are resistant to spills and vibrations. AGM batteries are designed in a way that prevents acid leaks. Leaving them on their side or upside down for days doesn't make a difference. Due to this reason, these batteries are perfect for off-road vehicles that are prone to rolling over. They are more resistant to damage from extreme temperatures. AGM batteries can also withstand freezing temperatures. It remains safe even if placed near the engine and exposed to heat.

Uses of AGM Batteries

AGM batteries are ideal for upper mid-range cars, SUVs, and premium cars. AGM batteries, which are maintenance-free and leakproof, are powerful and ideal for automatic start-stop systems. They also have excellent cold start capabilities. With an AGM battery's cycle stability, a warm engine can be repeatedly turned off and on without any restarting issues. Moreover, they provide sufficient reserves to maintain a consistent power supply during frequent stops and ensure reliable starting. For vehicles with automatic start-stop systems and recuperation, as well as cars with premium equipment and advanced accessories, an AGM battery is the ideal energy storage unit.

EFB Batteries

EFB batteries are an improved variant of the traditional wet-flooded technology. These batteries are designed for entry-level use and uniquely utilize gel battery chemistry, making them suitable for stop-start vehicles. The charging and discharging cycles for these vehicles need to be fast and frequent.

Charging of EFB Batteries

The most effective way to charge your EFB battery at home is by using a charger that is specifically made for EFB batteries. These chargers can charge your battery at voltages higher than what is typically found in car chargers, ensuring optimal battery health.

Advantages of EFB Batteries

EFB batteries offer numerous benefits compared to AGM batteries. The main advantage is that they have a longer cycle life. EFB batteries have a longer useful life compared to AGM batteries due to their increased cycle endurance.

In high-vibration applications, EFBs can be discharged more extensively compared to AGMs. This makes them ideal for motorcycles, which undergo significant shaking during use. In low-voltage scenarios, EFBs recharge much quicker than AGMs. An EFB can recharge faster than an AGM battery due to its ability to handle high energy levels without harm.

Disadvantages of EFB Batteries

AGM batteries have a lower tendency to experience sulfation than EFB batteries. When a battery's positive and negative plates become coated with sulfur, it is known as sulfation. This limits the battery's ability to utilize its full capacity. Failing to fully charge EFB batteries regularly leads to sulfation. Performance is significantly reduced as a result of this.

Uses of EFB Batteries

EFB batteries are designed for compact and mid-range cars equipped with start-stop technology. Conventional lead-acid batteries have been further developed into EFB batteries. The presence of Polyvlies material on the positive plate surface ensures an extended lifespan for the EFB. EFB batteries are known for their low internal resistance, resulting in double the charging cycles compared to regular starter batteries, and their high load capacity. 

EFB batteries are appropriate for powering cars that have basic automatic start-stop systems, as well as cars without start-stop but with demanding driving needs (such as urban traffic) or extensive equipment. If the car comes with an EFB battery, you can use another EFB battery as a replacement. A powerful AGM battery can be chosen for car owners seeking even greater performance or with demanding driving profiles and lots of urban traffic.

EFB vs AGM Batteries: What is the right choice?

EFB batteries are a good option for entry-level start-stop cars. If your car requires more electricity, especially those with larger engines, then an AGM battery would be a better choice. AGM batteries are a better option if you frequently drain your car battery during long drives.

AGM batteries are a good choice for frequent drivers as they are more resistant to being drained and can maintain their effectiveness after multiple charge cycles. With superior temperature resistance and lower internal resistance, these batteries offer a significantly extended lifespan.

For a large number of drivers, EFB and AGM batteries are the ideal choice. If you're in search of a durable battery that will endure for years, then either choice could work for you. An AGM battery might be a better choice if you need something that can endure extreme temperatures and other challenging conditions in the UAE

If you need help choosing the right battery for your vehicle, Fasttrack has professionals who can assist you. Get in touch with us now, and our specialists will assist you in making the optimal decision for your vehicle.