The abbreviation AGM stands for Absorbent Glass Mat (AGM) and means that the electrolyte in these batteries is bound in a glass fiber fleece. AGM batteries ensure higher start and supply reliability, are leak-proof and have been specially developed for vehicles with start-stop systems.
An intelligent battery sensor that has been additionally mounted on the battery's negative terminal monitors the battery condition. The measured values are transmitted to a higher-level control unit via the serial LIN communication interface.
Secondary battery
A second, so-called secondary battery has been additionally installed in this vehicle. Secondary batteries, also known as buffer or back-up batteries, support the vehicle electrical system when the engine has been switched off. The additional supply is managed by a battery control unit and it simultaneously prevents the batteries from discharging each other.
Alternator with overrunning alternator pulley
The alternator supplies power consumers with power while the engine is running and maintains the battery charge. The alternator output depends on the engine speed. The maximum alternator output is only generated above 2000 rpm. A charge regulator is installed in the alternator, which is also referred to as the alternator control unit. The charge controller has been connected to the engine control unit via a LIN interface. By mounting an overrunning alternator pulley only the driving force of one direction of rotation is transmitted to the alternator, thus reducing friction and wear.
Engine control unit
In this system, the charging system is intelligently controlled via the engine control unit (ECM). The central electronics module (CEM) sends a request about the desired charging voltage for the main battery to the engine control unit from where this request is forwarded to the alternator regulator. The charge signal lamp in the instrument cluster is controlled via the CAN network. At the same time, the engine control unit switches on the secondary battery via a relay for the charging process. The charging time of the secondary battery is calculated by the central electronics module and forwarded to the engine control unit.
Starter
The starter, also known as the starter motor, is required to start the internal combustion engine. Starters are electric motors that are briefly connected to the engine during the starting process via a ring gear that bring it to the desired starting speed. Depending on the design, the current consumption of the starter can be well over one hundred amperes. By reinforcing individual components, the starter has been designed for an increased number of start cycles over its entire service life