The application of the engine start stop battery system is becoming more and more popular. Special batteries are required, which are more advanced than conventional batteries and have a longer life, but the price is higher.
In cars equipped with a start-stop battery, ordinary standard batteries cannot be used, even if the capacity is large, they cannot withstand charging current much higher than the normal current, and their service life is limited. According to a test conducted by the American company Exide, in the case of simulating city driving, conventional batteries can be charged from 20,000 to 25,000 times, and the unique batteries noted above can be charged 60,000 times.
For models with intelligent generator control, conventional batteries are even less competent, as charging is done when accelerating and decelerating, and the battery current is even greater.
Types of Battery
There are two types of batteries commonly used on start-stop-equipped vehicles:
- EFB Battery
- AGM (Absorbed Glass Mat) Battery.
Compared with ordinary batteries, the first type of battery has many improvements in detail, and the second type is more advanced. Its plates are not immersed in the electrolyte (dilute sulfuric acid), but most of the electrolyte is absorbed by the porous glass fiber separator. In addition, the gas generated during the charging process will be attracted by chemical reactions, and the battery is also completely sealed, so it can be installed in the cab.
However, AGM batteries also have disadvantages. They do not withstand high temperatures, so do not install them near the engine, otherwise, they must provide good ventilation, as the MINI does.
The EFB battery is suitable for cars with a start-stop system without intelligent charging control, such as Fiat 500 and Alpha. Romeo Giulietta is equipped with an intelligent generator management system (such as BMW Efficient Dynamics), because of this, an AGM battery should be used. The ability to withstand a high-intensity charging current is mainly due to special insulating equipment, thinner mesh thickness, and a special mixture contained in the electrode plate, etc. to reduce internal resistance. In addition, unlike traditional batteries, the single substance that makes up an AGM battery compresses before entering the electrolytic cell, making it shock resistant.
Manufacturers have incorporated many of these technologies into EFB batteries, thereby extending their charge and discharge times so that they can handle high-intensity charging. It still does not match the level of AGM batteries.
In short, batteries are back in the spotlight of designers not only for electric and hybrid vehicles but also for conventional cars. So far, we have been saying about lead-acid batteries, but with this battery, the situation is much more complicated than before. Previously, there were no problems with charging the battery, but now you need to be vigilant to prevent damage.