In today's vehicles, the rising number of electrical loads presents a challenge to the battery. More than half of the vehicle breakdowns that are caused by the electrical system can be traced back to the lead-acid battery and could have been avoided by knowledge of the battery state. Additionally, new functions of "micro hybrid" vehicles, such as start-stop or intelligent alternator control, require exact knowledge of the battery state.
A battery management system (BMS) provides the necessary information by fast and reliable detection of the State-of-Charge (SoC), State-of-Health (SoH), and State-of-Function (SoF) in terms of cranking capability. So, the BMS is able to minimize the number of vehicle breakdowns due to unforeseen battery failure, to maximize lifetime and efficiency of the battery, and to enable CO2 saving functions. The key element of the BMS is an Intelligent Battery Sensor (IBS), which measures battery terminal voltage, current, and temperature and calculates the battery state.
The complete article (click here) describes the implementation of a BMS using state-of-the-art algorithms for calculation of SoC, SoH, and SoF and the efficient implementation of these on Freescal's IBS for lead-acid batteries, courtesy of Automotive Designline Europe.
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