In vehicles equipped with an automatic Start-Stop system, the battery faces increased demands due to several factors. These include the high charge throughput required to support numerous electrical consumers, such as steering wheel heaters, air conditioning systems, and safety features, which must remain operational even when the engine is off at traffic lights. Only EFB (Enhanced Flooded Batteries) and AGM (Absorbent Glass Mat) batteries are designed to meet the rigorous challenges of automatic Start-Stop systems.
EFB batteries are designed to meet the power requirements of:
- Vehicles with basic automatic Start-Stop systems.
- Cars without Start-Stop systems but with demanding driving conditions (e.g., urban traffic).
- Vehicles with extensive equipment but no Start-Stop functionality.
EFB batteries represent an advancement over traditional lead-acid batteries. They feature a Polyvlies material on the positive plate surface, which stabilizes the active material and extends battery life. The separators within EFB batteries have low resistance, enhancing the charging process. EFB batteries offer excellent cycle stability and load capacity, with the ability to endure twice as many charging cycles as conventional starter batteries, according to EN testing standards.
AGM batteries are ideal for vehicles with automatic Start-Stop systems with braking energy recovery (recuperation), or for cars with premium equipment and sophisticated accessories, as a conventional starter battery cannot handle the high power demands of these systems.
The electrolyte in an AGM battery (Absorbent Glass Mat) is held within an absorbent glass fleece, making the battery maintenance-free and leak-proof. Even if the battery casing is damaged, the battery acid remains contained. AGM batteries are known for their excellent cold-start performance, providing powerful starts for the starter motor and reducing its running time. Their cycle stability allows for multiple restarts of a warm engine within short intervals without restarting issues. Additionally, AGM batteries offer significant advantages in service life, with the ability to endure three times more charging cycles compared to conventional starter batteries.
Braking generates energy that would otherwise be wasted, but with braking energy recovery (recuperation), this energy can be harnessed. During braking, part of this energy is redirected into the vehicle's battery, provided the battery is suitable for recuperation. AGM batteries are designed for this purpose.
Conventional wet batteries (SLI) are typically used to start the engine once per journey. They reach full charge before the engine is started and are then recharged by the alternator while driving.
In vehicles with an automatic Start-Stop system, the battery must restart the engine multiple times during a trip. This causes the battery's charge level to drop repeatedly, while still needing to power electrical consumers during periods of engine stop. This increased demand places significant strain on the battery. AGM batteries are designed to handle this by operating in a partial charge range. They recharge during driving and achieve a full charge during recuperation. When the vehicle is stopped, the charge level drops due to the power needed for electrical consumers, creating space to store energy from the next braking event.
Because of this, batteries in vehicles with automatic Start-Stop batteries experience frequent and significant changes in charge state. The combination of discharging during engine starts, recharging by the alternator, and energy recuperation imposes substantial loads that only AGM batteries can reliably endure over time.
AGM batteries, in conjunction with the vehicle's energy management system, ensure a steady and dependable supply of power to the vehicle's electrical components while optimizing efficiency.
If your vehicle does not have Start-Stop technology, it may be equipped with a standard lead-acid battery. Before purchasing a replacement, check your current battery or consult your vehicle's manual to understand the technology used. Once you have this information, you can select the best replacement option. For additional guidance, feel free to reach out to our team of experts who will be happy to assist you with your choice.
