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AGM vs EFB Batteries, Which is Better?

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AGM vs EFB Batteries, Which is Better?

With the expansion of the Start-Stop engines, almost every vehicle rolling of the production line will either require an EFB or the higher performance AGM battery.

As environmental concerns escalate worldwide, so does the desire for electric vehicles. In South Africa alone, it’s predicted that the demand for lithium-ion batteries will continue to increase in the forthcoming years. As such, they’ll need better options to handle how an electric car functions.

EFB batteries are one such product that functions well with start-stop vehicles. Although they aren’t lithium-based, they’re considered an improvement over normal flooded lead-acid batteries. At the same time, they’re considered an entry-level option.

Here is your EFB battery guide and why you might choose them over the alternatives.

EFB Batteries

So what makes these types of batteries different from the other options in the market?

Enhanced flooded batteries (EFB) work much like other lead-acid batteries. The lead dioxide and acid inside the case generate a chemical reaction. An electrical charge is replenished by reversing this reaction.

Over time, the generated charge becomes weaker due to fewer sulfate ions in the acid.

EFB technology differs from other lead-acid batteries in that they utilize liquid electrolytes inside of them. Lead plates are another distinctive feature that absorbs and retain liquid electrolytes when combined with microfiber material.

The end result is a product that lasts longer and reduces the need for battery maintenance.

If your current car battery is failing, it may be a good idea to switch it with an EFB. These are especially good for start-stop vehicles, as they can handle deep discharges and have a larger capacity.

They’re an especially reliable option for entry-level vehicles due to their lower cost than other batteries on the market.

EFB vs AGM Batteries

EFBs aren’t the only option for your start-stop vehicle, though. The other option you may want to consider is an AGM battery. These differ from the former in how they function, the kind of electrical demands they can handle, and how well they charge.

If you’ve got an entry-level start-stop car, EFB batteries might be the right choice for you. However, if your car has a higher electricity demand (such as those with larger engines), an AGM battery is probably better suited to your needs. Also, if you use your car for longer drives and constantly drain the battery, AGM batteries are a better choice.

Frequent drivers should consider AGM batteries because they’re more resilient to being drained and can withstand multiple charge cycles without losing their effectiveness. These types of batteries have superior temperature resistance and lower internal resistance, which means they’ll last longer overall!

Pros of AGM Batteries

These batteries will last a long time. AGM batteries can last up to twice as long as conventional batteries in deep discharge cycles.

They’re also spill-proof and vibration resistant.

Because of their construction, AGM batteries can’t leak acid. It doesn’t matter if you leave them on their side or upside down for days at a time. Because of this, these batteries are great for off-road vehicles that are prone to rolling over during use.

They’re less susceptible to damage caused by extreme temperatures. An AGM battery won’t freeze in cold conditions like those found in Alaska or Canada. It also won’t explode when exposed to heat from sitting too close to your engine compartment.

AGM batteries are best suited for motorcycles, boats, cars, and RVs. In these applications, you can use AGM batteries in place of conventional lead-acid batteries. They will give you performance that is equal to or better than the conventional battery.

You can also use AGM batteries in off-the-grid power systems, such as solar panels. They’re useful for providing battery backup when there is no available grid power.

AGMs are ideal for anyone who needs more starting current from their vehicle than an EFB battery can provide

efb batteries
H9 agm-105 stop-start battery

Design and History

AGM, or Absorbed Glass Mat, batteries work just like standard batteries, except they have a fibreglass mat between the negative and positive plates. The electrolyte passes through the mat in a controlled manner without any danger of flooding it.

This also means that no free liquid will come out if the battery casing is broken. However, AGM batteries may have issues with extreme heat due to how little electrolyte is flowing through them.

These batteries have been around since the 1980s, and there are various options.

Meanwhile, the first EFB battery was released in 2008 to reduce fuel consumption and emissions. Although it is newer, it may not be the best option for your vehicle.

For example, your car may have been functioning perfectly well for years with an AGM battery. It wouldn’t make sense to switch it to an EFB then, as it may work best with the type it came with. However, you can always upgrade your standard battery for either one to see some improvement.

Start-Stop Functionality

One mechanism standard batteries struggle with is the newer start and stop engine systems. These systems work to reduce fuel consumption in high-traffic situations by managing when your engine runs.

In vehicles with this system, the engine stops whenever the vehicle comes to a stop as a result of the driver pressing on the brake. The engine then restarts when your foot is lifted off of the brake, allowing the vehicle to once again accelerate.

The problem with this system comes into play when you’re in heavy traffic on the highway. It’s not uncommon for a driver to have to continuously break and accelerate when dealing with bumper-to-bumper traffic. Things move at a slow pace, and this kind of encounter could go on for a while.

A conventional battery cannot handle this kind of strain and will likely stop working in a matter of months.

Meanwhile, both EFB and AGM batteries are well-suited for start-stop engines.


Both EFB and AGM batteries require special chargers in order to avoid overcharging them. The voltage shouldn’t exceed 14,4V. It’s important to check the battery case for things like ideal operating conditions and allowable charging voltage.

Always stop charging when the indicator goes down to 2,5A. Certain chargers may also have built-in control systems to prevent overcharging.

Benefits and Drawbacks of EFB Batteries

So what is it about EFB batteries that make them worth your investment? And are there any problems they have that might make you choose a different option?

One of the benefits of EFB technology is that it can deliver a starting current of up to 550A. In comparison, a conventional battery can only get up to 300A.

They last longer than standard batteries and charge much more quickly. You can expect good performance in colder weather. It’s even safe to store them for a couple of years without them suffering a significant loss in storage capacity.

As previously mentioned, EFB batteries are suitable for start-stop engine systems. They can handle the daily stressors of the modern roadway much better than standard batteries.

One of the problems with EFB batteries is that they have strict charging conditions. It’s all too easy to overcharge and damage them by boiling the electrolyte. In addition, AGM batteries are more powerful and may have more appeal to some vehicle owners.

Pros of EFB Batteries

EFB batteries have several advantages over AGM batteries. The most significant advantage is their longer cycle life. An EFB battery can withstand more cycles of charge and discharge than an AGM before it reaches the end of its useful life.

Another advantage is that EFB batteries can be discharged to a greater extent than AGMs in high-vibration applications. This makes them better suited for vehicles like motorcycles, where they’ll experience a lot of shaking while in operation.

Even in low-voltage situations, EFBs have a much shorter recharge time than AGMs. Because they’re capable of accepting large amounts of energy at once without damage, recharging EFB batteries takes less time than it would if you were using an

Buying the Right Batteries

If you’re not sure what type of battery your vehicle should get, you can’t go wrong with EFB batteries. They work well with start-stop vehicles, resist corrosion, and are protected from the elements. There’s no need to worry about maintaining them or developing electrical or fluid problems.


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