What does EFB mean in cars?

[McKhloe]

Automotive EFB batteries refer to Enhanced Flooded Batteries, which are the opposite of Absorbent Glass Mat (AGM) batteries. Definition of Flooded Battery: In a flooded battery, the remaining space inside the battery case after accounting for plates, separators, and other solid assembly components is completely filled with sulfuric acid electrolyte (the electrolyte composition may vary depending on the battery type). Since the electrolyte is in an abundant and excessive state, it is called a flooded battery. Function of Enhanced Flooded Battery: The Enhanced Flooded Battery is designed to address water evaporation and decomposition losses during usage. To adjust the electrolyte density, the battery's sealing cover is designed to be removable (i.e., it can be detached) for adding distilled water to regulate the electrolyte concentration.

[StRuby]

When I worked at the repair shop, customers often asked about EFB batteries. To put it simply, it's an upgraded version of a regular lead-acid battery. The three letters EFB stand for 'Enhanced Flooded Battery,' specifically designed for vehicles with start-stop systems. Nowadays, popular models like the new Corolla and Sylphy, which cost around 100,000 yuan, prefer using this type. Compared to regular batteries, EFB batteries have an extra layer of glass fiber separator, boosting charge-discharge capacity by three times. This means the battery won’t easily drain even when the engine repeatedly starts and stops at traffic lights. Last week, my neighbor with an older Sagitar replaced his battery, and the shop tricked him into installing a regular one. As a result, the start-stop system kept malfunctioning, and he eventually had to switch to an EFB. A reminder to everyone: always check the model label when replacing a battery—don’t install a regular one in a car with a start-stop system.

[McDominic]

I've been studying automotive parts for over a decade. EFB batteries are essentially still members of the lead-acid battery family. There are three common types of car batteries on the market: standard batteries, EFB batteries, and the more advanced AGM batteries. EFB batteries feature upgrades in electrolyte formulation and internal separators, costing about 30% less than AGM batteries. This type of battery is particularly suitable for Japanese cars or models with engines below 1.6 liters. Maintenance is simple—just keep the battery terminals clean. Additionally, I've noticed that many car owners in southern regions feel their batteries don't last long, but EFB batteries are actually ideal for high-temperature areas, as their water loss is only half that of standard batteries. Recently, battery testers have become popular in repair shops, capable of measuring a battery's remaining lifespan in just two minutes. I recommend checking every six months.