Many car owners plan long-distance driving trips, and auto repair shops also enter a highly busy period. In addition to routine maintenance and repair, frequent malfunctions in the winter include failure of the car start-stop system and depleted AGM batteries. However, many technicians have incomplete knowledge of relevant topics, and shops often neglect this area of business. Today, let's talk systematically about it.
The car start-stop system is a power transmission system. When the engine temporarily stops, such as at a red light, it shuts down, and the electrical energy required in the car is supplied by the battery instead of the engine, which can reduce fuel consumption and carbon dioxide emissions. The start-stop system is a complete set of systems, including a generator, battery, starter motor, battery management system, and power management system.
Compared with vehicles without the start-stop function, these components are designed completely differently, designed around frequent start-ups. The generator requires high charging current, the starter motor need to be suited for high-frequency start-ups, and the battery needs to be able to accommodate large currents for charging and discharging.
The battery is a vulnerable component with a relatively high replacement frequency. There are also many types of start-stop batteries: AGM batteries, EFB start-stop batteries, and ISS start-stop batteries, which can all meet start-stop requirements. Advanced start-stop cars mostly use AGM start-stop batteries.
The AGM start-stop battery is an AGM battery, but not all AGM batteries are start-stop batteries. AGM is just the name of the battery separator, which is called the glass fiber separator and is used in valve-regulated lead-acid batteries. Later, all valve-regulated lead-acid batteries were called AGM batteries.
Because the battery needs to meet high-frequency start-ups and the use of all kinds of electrical equipment in the car when the engine is not running, it needs to quickly supplement full electrical energy. Therefore, start-stop batteries are significantly different from previous car starting batteries.
The battery management system detects the CCA starting current, internal resistance, and voltage of the battery every minute. The power management system compares the data and executes various commands through the car computer, such as turning off the start-stop system charging and opening the start-stop system when the data meets the start-stop requirements.
The starting current, internal resistance, charging capacity, ability to accept high-current charging, rapid discharge capacity, and capacity of an ordinary starting battery are all unable to compare with those of a start-stop battery.
An ordinary battery can be installed on a vehicle equipped with a start-stop system and can also satisfy the starting requirements. However, it cannot be used for long because the battery management system detects data that does not conform to specifications. At the same time, high current charging and discharging can cause significant damage to ordinary starting batteries and lead to quick end of life and malfunction codes for in-car electronic devices.
In vehicles with power management systems such as BMW and Mercedes, even if the start-stop system is not present, AGM batteries are used. At that time, there was no start-stop system concept, so it was not called a start-stop battery. In reality, AGM start-stop batteries were used.