The AGM batteries (Absorbent Glass Material) are batteries that the latest generation cars are mounting to a greater extent.
Designed for vehicles equipped with STAR&STOP technologies and with regenerative braking.
The general characteristics of these batteries are excellent:
- High cold start capability
- They withstand deep discharges
- Designed for high peak loads
- Absorbed electrolyte instead of using sulfuric acid as the electrolyte, making them more environmentally friendly than conventional lead-acid batteries.
From FQS BATTERY We regularly hear questions about whether an AGM battery can be installed in a car that has an EFB battery and vice versa.
On many occasions we also hear that "Where there is an EFB, you can put an AGM, but where there is an AGM, you can't put an EFB.".
And we realize that a vital consideration is escaping. And that is the AGM battery charging requirements They are different from the requirements for conventional and EFB batteries. Overcharging or undercharging your AGM battery will permanently damage it and significantly reduce its lifespan.
So, if we want to install an AGM battery in a vehicle equipped with a standard alternator charging system designed for flooded lead-acid batteries, we'll run into serious problems. The AGM battery will either undercharge or overcharge. Its lifespan will be much shorter and it will discharge much more quickly.
In addition, vehicles that are already certain years old lack of the floating charge state* of the battery. In these cases, if we install an AGM battery, we considerably increase the risk of overheating, for example, on long trips.
*Float charging is the process by which, when the battery is already charged to 100%, the alternator operates at low, constant levels to compensate for self-discharge but at levels that do not overheat the battery.
REPROGRAM ALTERNATOR CHARGE VOLTAGE
Many newer vehicles now offer the ability to reprogram and adjust the charging voltage to what an AGM battery actually needs without damaging it. When installing the battery, it requires programming that directly adjusts the charging levels.
In addition to regulating the charge levels, you must ensure that it has a regulator that not only the charging voltage levels but also the charging current limit are correctly set. Otherwise, the AGM battery will not reach the charging limit, weakening its capacity and lifespan.
TO TAKE INTO ACCOUNT
AGM batteries, which are truly SUPER BATTERIES, are much more sensitive to high temperatures than other batteries. Exposure to high temperatures will significantly reduce their lifespan and performance.
It's not ideal for them to be installed under the hood, as in many conventional vehicles. Because depending on the area where they live, if they are installed in that location, they will reach high temperatures, and their lifespan and performance will be compromised.
If we look at cars that come standard with AGM batteries, they are usually located under the passenger seat, in the trunk, or in some other more protected location.
The proximity of the battery to the engine will also cause it to perceive more heat when the car is running. It's not just the ambient temperature that affects it, as we can see.
REGENERATIVE BRAKING
If we think about regenerative braking, heavy braking generates a very high peak load in a very short period of time.
These peaks are not supported by EFB batteries, much less by conventional ones. Furthermore, these peaks would occur with every braking action. In other words, if we were constantly, or at least frequently, using the battery improperly, one that it was neither designed nor capable of handling.
In the graph below we can see these charging and discharging peaks according to the different technologies.
SO OBVIOUSLY WE CAN'T PUT A
EFB BATTERY WHERE AN AGM BATTERY IS REQUIRED
OUR RECOMMENDATION
The recommendation we make from FQS BATTERY is to select for the vehicle the same type of battery that comes standardThe manufacturer itself will install a battery with the technology and features that will ensure the vehicle delivers optimal performance, and for which its systems are designed.
If you decide to replace your EFB battery with an AGM battery, you'll need to consider the above points to ensure the replacement will keep your vehicle running under optimal conditions. Otherwise, the battery will last much less than expected and won't perform as well as desired.
However, switching from a conventional battery to a EFB battery It doesn't pose any problems or risks. In fact, that's an improvement. No different requirements are needed. The change will mean a better-performing battery, longer-lasting with up to three times the cycle speed, the greatest resistance to vibrations for passenger cars, and a higher starting capacity. Regardless of whether the car has a START&STOP system.
